Processes for producing aldehyde acids or salts

ABSTRACT

This invention relates in part to processes for producing one or more substituted or unsubstituted aldehyde acids or salts, e.g., 5-formylvaleric acid or salt, which comprises subjecting one or more substituted or unsubstituted alkadienes, e.g., butadiene, to hydroxycarbonylation in the presence of a hydroxycarbonylation catalyst, e.g., a metal-organophosphorus ligand complex catalyst, and optionally neutralization with a base to produce one or more substituted or unsubstituted unsaturated acids or salts, e.g., pentenoic acid or salt, and subjecting said one or more substituted or unsubstituted unsaturated acids or salts to hydroformylation in the presence of a hydroformylation catalyst, e.g., a metal-organophosphorus ligand complex catalyst, to produce said one or more substituted or unsubstituted aldehyde acids or salts and/or one or more substituted or unsubstituted epsilon caprolactam precursors. This invention also relates in part to reaction mixtures containing one or more substituted or unsubstituted aldehyde acids or salts as the principal product(s) of reaction.

BRIEF SUMMARY OF THE INVENTION

1. Technical Field

This invention relates in part to processes for producing one or moresubstituted or unsubstituted aldehyde acids or salts. This inventionalso relates in part to reaction mixtures containing one or moresubstituted or unsubstituted aldehyde acids or salts as the principalproduct(s) of reaction.

2. Background of the Invention

Formylvaleric acid is a valuable intermediate which is useful, forexample, in the production of epsilon caprolactam. The processescurrently used to produce formylvaleric acid have various disadvantages.For example, the prior art processes to formylvaleric acid are multistepoperations involving more than one reaction vessel. Accordingly, itwould be desirable to produce epsilon caprolactam precursors by aprocess which does not have the disadvantages of prior art processes.

DISCLOSURE OF THE INVENTION

It has been discovered that alkadienes, e.g., butadiene, can behydroxycarbonylated and optionally neutralized to unsaturated acids orsalts, e.g., pentenoic acids or pentenoic acid salts, and theunsaturated acids or salts hydroformylated to aldehyde acids or salts,e.g., 5-formylvaleric acid or 5-formylvaleric acid salt, in a singlestep process in high selectivities and high normal:branched isomerratios. In particular, it has been surprisingly discovered thatalkadienes can be converted to unsaturated acids or salts and theunsaturated acids or salts converted to aldehyde acids or salts in highselectivities in a single step process by conducting thehydroxycarbonylation and hydroformylation in the presence of certainmetal-ligand complex catalysts and optionally free ligands. In addition,through the use of bases in accordance with this invention, the acidcatalyzed degradation of organophosphite ligands and/or deactivation ofmetal-organophosphite ligand complex catalysts can be prevented orminimized. It has been further discovered that the hydroxycarbonylationand hydroformylation processes of this invention can achieve high ratesof butadiene conversion and unsaturated acid or salt conversion atrelatively mild conditions of temperature and pressure. Also, the use ofbases to prepare salts of unsaturated acids and salts of aldehyde acidsmay facilitate recovery of products by, for example, phase separation orsolvent extraction. Further, there is no need to separate theunsaturated acids or salts from the hydroxycarbonylation catalyst priorto conducting the hydroformylation reaction, e.g., the process may beconducted in a single step.

This invention relates to a process for producing one or moresubstituted or unsubstituted aldehyde acids, e.g., 5-formylvaleric acid,which comprises subjecting one or more substituted or unsubstitutedalkadienes, e.g., butadiene, to hydroxycarbonylation in the presence ofa hydroxycarbonylation catalyst, e.g., a metal-organophosphorus ligandcomplex catalyst, to produce one or more substituted or unsubstitutedunsaturated acids, e.g., pentenoic acids, and subjecting said one ormore substituted or unsubstituted unsaturated acids to hydroformylationin the presence of a hydroformylation catalyst, e.g., ametal-organophosphorus ligand complex catalyst, to produce said one ormore substituted or unsubstituted aldehyde acids and/or one or moresubstituted or unsubstituted epsilon caprolactam precursors. Thehydroxycarbonylation and hydroformylation reaction conditions may be thesame or different and the hydroxycarbonylation and hydroformylationcatalysts may be the same or different.

This invention also relates to a process for producing one or moresubstituted or unsubstituted aldehyde acid salts, e.g., 5-formylvalericacid salt, which comprises subjecting one or more substituted orunsubstituted alkadienes, e.g., butadiene, to hydroxycarbonylation inthe presence of a hydroxycarbonylation catalyst, e.g., ametal-organophosphorus ligand complex catalyst, and neutralization witha base to produce one or more substituted or unsubstituted unsaturatedacid salts, e.g., pentenoic acid salts, and subjecting said one or moresubstituted or unsubstituted unsaturated acid salts to hydroformylationin the presence of a hydroformylation catalyst, e.g., ametal-organophosphorus ligand complex catalyst, to produce said one ormore substituted or unsubstituted aldehyde acid salts and/or one or moresubstituted or unsubstituted epsilon caprolactam precursors. Thehydroxycarbonylation and hydroformylation reaction conditions may be thesame or different and the hydroxycarbonylation and hydroformylationcatalysts may be the same or different.

This invention further relates to a process for producing one or moresubstituted or unsubstituted aldehyde acids, e.g., 5-formylvalericacids, which comprises reacting one or more substituted or unsubstitutedalkadienes with carbon monoxide and water in the presence of a catalyst,e.g., metal-organophosphorus ligand complex catalyst, and a promoter toproduce one or more substituted or unsubstituted unsaturated acids, andreacting said one or more substituted or unsubstituted unsaturated acidswith carbon monoxide and hydrogen in the presence of a metal-ligandcomplex catalyst, e.g., metal-organophosphorus ligand complex catalyst,and optionally free ligand to produce said one or more substituted orunsubstituted aldehyde acids and/or one or more substituted orunsubstituted epsilon caprolactam precursors.

This invention yet further relates to a process for producing one ormore substituted or unsubstituted aldehyde acid salts, e.g.,5-formylvaleric acid salts, which comprises reacting one or moresubstituted or unsubstituted alkadienes with carbon monoxide and waterin the presence of a catalyst, e.g., metal-organophosphorus ligandcomplex catalyst, and a promoter and a base to produce one or moresubstituted or unsubstituted unsaturated acid salts, and reacting saidone or more substituted or unsubstituted unsaturated acid salts withcarbon monoxide and hydrogen in the presence of a metal-ligand complexcatalyst, e.g., metal-organophosphorus ligand complex catalyst, andoptionally free ligand to produce said one or more substituted orunsubstituted aldehyde acid salts and/or one or more substituted orunsubstituted epsilon caprolactam precursors.

This invention further relates in part to a process for producing abatchwise or continuously generated reaction mixture comprising:

(1) one or more substituted or unsubstituted aldehyde acids, e.g.,5-formylvaleric acid, and/or one or more substituted or unsubstitutedepsilon caprolactam precursors;

(2) optionally one or more substituted or unsubstituted aldehyde acidsalts, e.g., formylvaleric acid salts such as triethylammonium5-formylvalerate and ammonium 5-formylvalerate;

(3) optionally one or more substituted or unsubstituted unsaturatedacids, e.g., pentenoic acids such as cis-3-pentenoic acids,trans-3-pentenoic acids, 4-pentenoic acid, cis-2-pentenoic acids and/ortrans-2-pentenoic acids;

(4) optionally one or more substituted or unsubstituted unsaturated acidsalts, e.g., pentenoic acid salts such as triethylammonium 3-pentenoateand ammonium 3-pentenoate;

(5) optionally one or more substituted or unsubstituted saturated acids,e.g., valeric acid or adipic acid;

(6) optionally one or more substituted or unsubstituted saturated acidsalts, e.g., triethylammonium valerate; and

(7) one or more substituted or unsubstituted alkadienes, e.g.,butadiene; wherein the weight ratio of component (1) to the sum ofcomponents (2), (3), (4), (5) and (6) is greater than about 0.1,preferably greater than about 0.25, more preferably greater than about1.0; and the weight ratio of component (7) to the sum of components (1),(2), (3), (4), (5) and (6) is about 0 to about 100, preferably about0.001 to about 50; which process comprises subjecting one or moresubstituted or unsubstituted alkadienes, e.g., butadiene, tohydroxycarbonylation in the presence of a hydroxycarbonylation catalyst,e.g., a metal-organophosphorus ligand complex catalyst, to produce oneor more substituted or unsubstituted unsaturated acids, e.g., pentenoicacids, and subjecting said one or more substituted or unsubstitutedunsaturated acids to hydroformylation in the presence of ahydroformylation catalyst, e.g., a metal-organophosphorus ligand complexcatalyst, to produce said batchwise or continuously generated reactionmixture.

This invention further relates in part to a process for producing abatchwise or continuously generated reaction mixture comprising:

(1) one or more substituted or unsubstituted aldehyde acid salts, e.g.,formylvaleric acid salts such as triethylammonium 5-formylvalerate andammonium 5-formylvalerate, and/or one or more substituted orunsubstituted epsilon caprolactam precursors;

(2) optionally one or more substituted or unsubstituted aldehyde acids,e.g., 5-formylvaleric acid;

(3) optionally one or more substituted or unsubstituted unsaturated acidsalts, e.g., pentenoic acid salts such as triethylammonium 3-pentenoateand ammonium 3-pentenoate;

(4) optionally one or more substituted or unsubstituted unsaturatedacids, e.g., pentenoic acids such as cis-3-pentenoic acids,trans-3-pentenoic acids, 4-pentenoic acid, cis-2-pentenoic acids and/ortrans-2-pentenoic acids; and

(5) optionally one or more substituted or unsubstituted saturated acidsalts, e.g., triethylammonium valerate;

(6) optionally one or more substituted or unsubstituted saturated acids,e.g., valeric acid or adipic acid; and

(7) one or more substituted or unsubstituted alkadienes, e.g.,butadiene; wherein the weight ratio of component (1) to the sum ofcomponents (2), (3), (4), (5) and (6) is greater than about 0.1,preferably greater than about 0.25, more preferably greater than about1.0; and the weight ratio of component (7) to the sum of components (1),(2), (3),(4), (5) and (6) is about 0 to about 100, preferably about0.001 to about 50; which process comprises subjecting one or moresubstituted or unsubstituted alkadienes, e.g., butadiene, tohydroxycarbonylation in the presence of a hydroxycarbonylation catalyst,e.g., a metal-organophosphorus ligand complex catalyst, andneutralization with a base to produce one or more substituted orunsubstituted unsaturated acid salts, e.g., pentenoic acid salts, andsubjecting said one or more substituted or unsubstituted unsaturatedacid salts to hydroformylation in the presence of a hydroformylationcatalyst, e.g., a metal-organophosphorus ligand complex catalyst, toproduce said batchwise or continuously generated reaction mixture.

This invention also relates to a process for producing a reactionmixture comprising one or more substituted or unsubstituted aldehydeacids, e.g., 5-formylvaleric acid, which process comprises subjectingone or more substituted or unsubstituted alkadienes, e.g., butadiene, tohydroxycarbonylation in the presence of a hydroxycarbonylation catalyst,e.g., a metal-organophosphorus ligand complex catalyst, to produce oneor more substituted or unsubstituted unsaturated acids, e.g., pentenoicacids, and subjecting said one or more substituted or unsubstitutedunsaturated acids to hydroformylation in the presence of ahydroformylation catalyst, e.g., a metal-organophosphorus ligand complexcatalyst, to produce said reaction mixture comprising one or moresubstituted or unsubstituted aldehyde acids.

This invention also relates to a process for producing a reactionmixture comprising one or more substituted or unsubstituted aldehydeacid salts, e.g., 5-formylvaleric acid salt, which process comprisessubjecting one or more substituted or unsubstituted alkadienes, e.g.,butadiene, to hydroxycarbonylation in the presence of ahydroxycarbonylation catalyst, e.g., a metal-organophosphorus ligandcomplex catalyst, and neutralization with a base to produce one or moresubstituted or unsubstituted unsaturated acid salts, e.g., pentenoicacid salts, and subjecting said one or more substituted or unsubstitutedunsaturated acid salts to hydroformylation in the presence of ahydroformylation catalyst, e.g., a metal-organophosphorus ligand complexcatalyst, to produce said one reaction mixture comprising one or moresubstituted or unsubstituted aldehyde acid salts.

The processes of this invention can achieve high selectivities ofbutadiene to aldehyde acid or salt. Selectivities of aldehyde acid orsalt of at least 10% by weight and up to 75% by weight or greater may beachieved by the processes of this invention.

This invention yet further relates in part to a batchwise orcontinuously generated reaction mixture comprising:

(1) one or more substituted or unsubstituted aldehyde acids, e.g.,5-formylvaleric acid, and/or one or more substituted or unsubstitutedepsilon caprolactam precursors;

(2) optionally one or more substituted or unsubstituted aldehyde acidsalts, e.g., formylvaleric acid salts such as triethylammonium5-formylvalerate and ammonium 5-formylvalerate;

(3) optionally one or more substituted or unsubstituted unsaturatedacids, e.g., pentenoic acids such as cis-3-pentenoic acids,trans-3-pentenoic acids, 4-pentenoic acid, cis-2-pentenoic acids and/ortrans-2-pentenoic acids;

(4) optionally one or more substituted or unsubstituted unsaturated acidsalts, e.g., pentenoic acid salts such as triethylammonium 3-pentenoateand ammonium 3-pentenoate;

(5) optionally one or more substituted or unsubstituted saturated acids,e.g., valeric acid or adipic acid;

(6) optionally one or more substituted or unsubstituted saturated acidsalts, e.g., triethylammonium valerate; and

(7) one or more substituted or unsubstituted alkadienes, e.g.,butadiene; wherein the weight ratio of component (1) to the sum ofcomponents (2), (3), (4), (5) and (6) is greater than about 0.1,preferably greater than about 0.25, more preferably greater than about1.0; and the weight ratio of component (7) to the sum of components (1),(2), (3), (4), (5) and (6) is about 0 to about 100, preferably about0.001 to about 50.

This invention also relates in part to a batchwise or continuouslygenerated reaction mixture comprising:

(1) one or more substituted or unsubstituted aldehyde acid salts, e.g.,formylvaleric acid salts such as triethylammonium 5-formylvalerate andammonium 5-formylvalerate, and/or one or more substituted orunsubstituted epsilon caprolactam precursors;

(2) optionally one or more substituted or unsubstituted aldehyde acids,e.g., 5-formylvaleric acid;

(3) optionally one or more substituted or unsubstituted unsaturated acidsalts, e.g., pentenoic acid salts such as triethylammonium 3-pentenoateand ammonium 3-pentenoate;

(4) optionally one or more substituted or unsubstituted unsaturatedacids, e.g., pentenoic acids such as cis-3-pentenoic acids,trans-3-pentenoic acids, 4-pentenoic acid, cis-2-pentenoic acids and/ortrans-2-pentenoic acids;

(5) optionally one or more substituted or unsubstituted saturated acidsalts, e.g., triethylammonium valerate;

(6) optionally one or more substituted or unsubstituted saturated acids,e.g., valerie acid or adipic acid; and

(7) one or more substituted or unsubstituted alkadienes, e.g.,butadiene; wherein the weight ratio of component (1) to the sum ofcomponents (2), (3), (4), (5) and (6) is greater than about 0.1,preferably greater than about 0.25, more preferably greater than about1.0; and the weight ratio of component (7) to the sum of components (1),(2), (3), (4), (5) and (6) is about 0 to about 100, preferably about0.001 to about 50.

This invention further relates in part to a reaction mixture comprisingone or more substituted or unsubstituted aldehyde acids, e.g.,5-formylvaleric acid, in which said reaction mixture is prepared by aprocess which comprises subjecting one or more substituted orunsubstituted alkadienes, e.g., butadiene, to hydroxycarbonylation inthe presence of a hydroxycarbonylation catalyst, e.g., ametal-organophosphorus ligand complex catalyst, to produce one or moresubstituted or unsubstituted unsaturated acids, e.g., pentenoic acids,and subjecting said one or more substituted or unsubstituted unsaturatedacids to hydroformylation in the presence of a hydroformylationcatalyst, e.g., a metal-organophosphorus ligand complex catalyst, toproduce said reaction mixture comprising one or more substituted orunsubstituted aldehyde acids.

This invention further relates in part to a reaction mixture comprisingone or more substituted or unsubstituted aldehyde acid salts, e.g.,5-formylvaleric acid salt, in which said reaction mixture is prepared bya process which comprises subjecting one or more substituted orunsubstituted alkadienes, e.g., butadiene, to hydroxycarbonylation inthe presence of a hydroxycarbonylation catalyst, e.g., ametal-organophosphorus ligand complex catalyst, and neutralization witha base to produce one or more substituted or unsubstituted unsaturatedacid salts, e.g., pentenoic acid salts, and subjecting said one or moresubstituted or unsubstituted unsaturated acid salts to hydroformylationin the presence of a hydroformylation catalyst, e.g., ametal-organophosphorus ligand complex catalyst, to produce said reactionmixture comprising one or more substituted or unsubstituted aldehydeacid salts.

The reaction mixtures of this invention are distinctive insofar as theprocesses for their preparation achieve the generation of highselectivities of aldehyde acids or salts in a manner which can besuitably employed in a commercial process for the manufacture ofaldehyde acids or salts. In particular, the reaction mixtures of thisinvention are distinctive insofar as the processes for their preparationallow for the production of aldehyde acids or salts in relatively highyields without generating large amounts of byproducts.

DETAILED DESCRIPTION

Hydroxycarbonylation Stage or Reaction

The hydroxycarbonylation process involves converting one or moresubstituted or unsubstituted alkadienes, e.g., butadiene, to one or moresubstituted or unsubstituted unsaturated acids, e.g., cis-3-pentenoicacids, trans-3-pentenoic acids, 4-pentenoic acid, cis-2-pentenoic acidsand/or trans-2-pentenoic acids. As used herein, the term"hydroxycarbonylation" is contemplated to include all permissiblehydroxycarbonylation processes which involve converting one or moresubstituted or unsubstituted alkadienes to one or more substituted orunsubstituted unsaturated acids. A preferred hydroxycarbonylationprocess useful in this invention is disclosed in U.S. patent applicationSer. No. (08/839578), filed on an even date herewith, the disclosure ofwhich is incorporated herein by reference. In general, thehydroxycarbonylation stage or reaction comprises reacting one or moresubstituted or unsubstituted alkadienes with carbon monoxide and waterin the presence of a catalyst and a promoter to produce one or moresubstituted or unsubstituted unsaturated acids.

The hydroxycarbonylation reaction mixtures employable herein typicallyincludes any solution derived from any correspondinghydroxycarbonylation process that contains at least some amount of thefollowing ingredients or components, i.e., the unsaturated acid product,a catalyst, unreacted alkadiene, carbon monoxide gas and water, saidingredients corresponding to those employed and/or produced by thehydroxycarbonylation process from whence the hydroxycarbonylationreaction mixture may be derived. It is to be understood that thehydroxycarbonylation reaction mixture compositions employable herein canand normally will contain minor amounts of additional ingredients suchas those which have either been deliberately employed in thehydroxycarbonylation process or formed in situ during said process.Examples of such ingredients that can also be present include a promotersuch as a carboxylic acid, and in situ formed type products, such assaturated or unsaturated hydrocarbons and/or unreacted isomerizedolefins corresponding to the alkadiene starting materials, andbyproducts, as well as other inert co-solvent type materials orhydrocarbon additives, if employed.

Alkadienes useful in the hydroxycarbonylation are known materials andcan be prepared by conventional processes. Reaction mixtures comprisingalkadienes may be useful herein. The amounts of alkadienes employed inthe hydroxycarbonylation is not narrowly critical and can be any amountssufficient to produce unsaturated acids, preferably in highselectivities and acceptable rates. Alkadienes may be fed eitherbatchwise or continuously.

Illustrative substituted and unsubstituted alkadiene starting materialsuseful in the hydroxycarbonylation reaction include, but are not limitedto, conjugated aliphatic diolefins represented by the formula: ##STR1##wherein R₁ and R₂ are the same or different and are hydrogen, halogen ora substituted or unsubstituted hydrocarbon radical. The alkadienes canbe linear or branched and can contain substituents (e.g., alkyl groups,halogen atoms, amino groups or silyl groups). Illustrative of suitablealkadiene starting materials are butadiene, isoprene, dimethyl butadieneand cyclopentadiene. Most preferably, the alkadiene starting material isbutadiene itself (CH₂ ═CH--CH═CH₂). For purposes of this invention, theterm "alkadiene" is contemplated to include all permissible substitutedand unsubstituted conjugated diolefins, including all permissiblemixtures comprising one or more substituted or unsubstituted conjugateddiolefins. Illustrative of suitable substituted and unsubstitutedalkadienes (including derivatives of alkadienes) include thosepermissible substituted and unsubstituted alkadienes described inKirk-Othmer, Encyclopedia of Chemical Technology, Third Edition, 1984,the pertinent portions of which are incorporated herein by reference.

The catalysts useful in the hydroxycarbonylation process include, forexample, Group 8, 9 and 10 metals or metal complexes (supported orunsupported), Group 8, 9 and 10 metal halides and esters (e.g., PdCl₂and PdI₂), palladium bis(dibenzylidene acetone), Pd(OAc)₂, palladium oncarbon, dicarbonylacetylacetonato rhodium (I) (Rh(CO)₂ acac), RhCl₃, Co₂(CO)₈, Group 8, 9 and 10 metal-ligand complex catalysts and the like.The hydroxycarbonylation catalysts may be in homogeneous orheterogeneous form. Such catalysts may be prepared by methods known inthe art. Suitable metal-ligand complex catalysts useful in thisinvention are described more fully hereinbelow.

The permissible metals which make up the metal-ligand complex catalystsinclude Group 8, 9 and 10 metals selected from rhodium (Rh), cobalt(Co), iridium (Ir), ruthenium (Ru), iron (Fe), nickel (Ni), palladium(Pd), platinum (Pt), osmium (Os) and mixtures thereof, with thepreferred metals being palladium, rhodium, cobalt, iridium andruthenium, more preferably palladium, rhodium, cobalt and ruthenium,especially palladium. The permissible ligands include, for example,organophosphorus, organoarsenic and organoantimony ligands, or mixturesthereof, preferably organophosphorus ligands. The permissibleorganophosphorus ligands which make up the metal-ligand complexesinclude organophosphines, e.g., mono-, di-, tri- andpoly-(organophosphines), and organophosphites, e.g., mono-, di-, tri-and poly-(organophosphites). Other permissible organophosphorus ligandsinclude, for example, organophosphonites, organophosphinites, aminophosphines and the like. Other permissible ligands include, for example,heteroatom-containing ligands such as 2,2'-bipyridyl and the like. Stillother permissible ligands include, for example, heteroatom-containingligands such as described in U.S. patent application Ser. No.(08/818,781), filed Mar. 10, 1997, the disclosure of which isincorporated herein by reference. Mixtures of such ligands may beemployed if desired in the metal-ligand complex catalyst and/or freeligand and such mixtures may be the same or different. By "free ligand"is meant ligand that is not complexed with (tied to or bound to) themetal, e.g., palladium atom, of the complex catalyst. This invention isnot intended to be limited in any manner by the permissible ligands ormixtures thereof. It is to be noted that the successful practice of thisinvention does not depend and is not predicated on the exact structureof the metal-ligand complex species, which may be present in theirmononuclear, dinuclear and/or higher nuclearity forms. Indeed, the exactstructure is not known. Although it is not intended herein to be boundto any theory or mechanistic discourse, it appears that the catalyticspecies may in its simplest form consist essentially of the metal incomplex combination with the ligand and carbon monoxide when used.

As noted the hydroxycarbonylation reactions involve the use of ametal-ligand complex catalyst as described herein. Of course mixtures ofsuch catalysts can also be employed if desired. The amount ofmetal-ligand complex catalyst present in the reaction medium of a givenhydroxycarbonylation reaction need only be that minimum amount necessaryto provide the given metal concentration desired to be employed andwhich will furnish the basis for at least the catalytic amount of metalnecessary to catalyze the particular hydroxycarbonylation reactioninvolved. In general, the catalyst concentration can range from severalparts per million to several percent by weight. Organophosphorus ligandscan be employed in the above-mentioned catalysts in a molar ratio ofgenerally from about 0.5:1 or less to about 1000:1 or greater. Thecatalyst concentration will be dependent on the hydroxycarbonylationreaction conditions and solvent employed.

In general, the organophosphorus ligand concentration inhydroxycarbonylation reaction mixtures may range from between about0.005 and 25 weight percent based on the total weight of the reactionmixture. Preferably the ligand concentration is between 0.01 and 15weight percent, and more preferably is between about 0.05 and 10 weightpercent on that basis.

In general, the concentration of the metal in the hydroxycarbonylationreaction mixtures may be as high as about 2000 parts per million byweight or greater based on the weight of the reaction mixture.Preferably the metal concentration is between about 50 and 1500 partsper million by weight based on the weight of the reaction mixture, andmore preferably is between about 70 and 1200 parts per million by weightbased on the weight of the reaction mixture.

In addition to the metal-ligand complex catalyst, free ligand (i.e.,ligand that is not complexed with the palladium metal) may also bepresent in the hydroxycarbonylation reaction medium. The free ligand maycorrespond, for example, to any of the above-definedphosphorus-containing ligands discussed above as employable herein. Itis preferred that the free ligand be the same as the ligand of themetal-ligand complex catalyst employed. However, such ligands need notbe the same in any given process. The hydroxycarbonylation reaction mayinvolve up to 100 moles, or higher, of free ligand per mole of metal inthe hydroxycarbonylation reaction medium. Preferably thehydroxycarbonylation reaction is carried out in the presence of fromabout 0.25 to about 50 moles of coordinatable phosphorus, and morepreferably from about 0.5 to about 10 moles of coordinatable phosphorusper mole of metal present in the reaction medium; said amounts ofcoordinatable phosphorus being the sum of both the amount ofcoordinatable phosphorus that is bound (complexed) to the palladiummetal present and the amount of free (non-complexed) coordinatablephosphorus present. Of course, if desired, make-up or additionalcoordinatable phosphorus can be supplied to the reaction medium of thehydroxycarbonylation reaction at any time and in any suitable manner,e.g. to maintain a predetermined level of free ligand in the reactionmedium.

In an embodiment, the hydroxycarbonylation reaction involves convertingbutadiene in the liquid phase in the presence of carbon monoxide, water,palladium and an organic phosphorus, antimony or arsenic ligand to areaction mixture comprising pentenoic acids, e.g., cis-3-pentenoicacids, trans-3-pentenoic acids, 4-pentenoic acid, cis-2-pentenoic acidsand/or trans-2-pentenoic acids.

The palladium may be present in the reaction mixture as a heterogeneouspalladium compound or as a homogeneous palladium compound. However,homogeneous systems are preferred. Since palladium in situ forms acomplex with the ligand, the choice of the initial palladium compound isin general not critical. Examples of homogeneous palladium compounds arepalladium salts of, for example, nitric acid, sulfonic acid, alkanecarboxylic acids with not more than 12 carbon atoms or hydrogenhalogenides (F, Cl, Br, I), but metallic palladium may also be used.Examples of such palladium compounds are PdCl₂, PdBr₂, PdI₂, Na₂ PdI₄,K₂ PdI₄, PdCl₂ (benzonitrile)₂ and bis(allylpalladium chloride). Anothergroup of suitable halogen-free palladium compounds are palladiumcomplexes such as palladium acetylacetonate (Pd(acac)₂), Pd(II) acetate,Pd(NO₃)₂, and palladium (benzylidene acetone)₂. An example of a suitableheterogeneous palladium compound is palladium on an ion exchange resin,such as for instance an ion exchange resin containing sulfonic acidgroups.

The preferred ligand:palladium molar ratio is generally between about1:1 and 10:1. When this ratio is lower, palladium can precipitate,whereas when this ratio is higher, the catalytic effect is weaker andbyproducts such as vinyl cyclohexene and high molecular weight productscan form. The optimum ratio will depend on the choice of the specificorganic groups bounded to the phosphorus, arsenic or antimony atoms. Thehydroxycarbonylation can optionally be carried out in the presence ofone or more phosphine ligands. The phosphine:organophosphorus (e.g.,organophosphite) ligand molar ratio may range between about 1:10 and10:1.

When a complex of the ligand and palladium is separately prepared beforebeing added to the hydroxycarbonylation reaction, an improved activityof the catalyst and an improved selectivity to the desired 3- and4-pentenoic acids may occur compared to the situation in which thiscomplex may be formed in situ. Such a complex of palladium and ligand,hereinafter called catalyst precursor, can be prepared by mixing apalladium compound as described above with the ligand. This mixing ispreferably performed in a solvent. Temperature and pressure are notcritical. The temperature can be, for example, between about 0° C. and100° C. The pressure can be, for example, atmospheric pressure. Themixing is preferably performed in the absence of air. Examples ofpossible solvents include organic solvents, for example, benzene,toluene, xylene, or aliphatic solvents, for example, hexane, methylpentenoate, methanol, acetone and ethanol, or the pentenoic acidproducts. Preferably the catalyst precursor is isolated from the mixtureby crystallization of the catalyst precursor under, for example,atmospheric pressure. The solid catalyst precursor can be separated fromthe solvent by, for example, filtration or evaporation of the solvent.The solid catalyst precursor can be easily supplied to thehydroxycarbonylation reaction by, for example, dissolving the catalystprecursor in one of the reactants or solvents and supplying theresulting mixture to the reaction.

As indicated above, the hydroxycarbonylation is preferably carried outin the presence of a promoter. Suitable promoters include, for example,protonic organic acids, inorganic acids, Lewis acids, e.g., BF₃, andprecursors capable of generating acids under hydroxycarbonylationconditions. The protonic organic acids are, for example, carboxylicacids and sulfonic acids with 1 to 30 carbon atoms. These carboxylic andsulfonic acids may be substituted with hydroxy, C₁ -C₄ alkoxy, amine andhalogenide groups, for example, chloride and bromide. Examples ofpreferred suitable carboxylic acids include benzoic acid or derivedcompounds, such as 2,4,6-trimethyl benzoic acid, meta- and parahydroxybenzoic acid, and product 3- and/or 4-pentenoic acids. Examples ofpreferred suitable sulfonic acids include methanesulfonic acid,trifluoromethanesulfonic acid and para-toluenesulfonic acid. Exampleinorganic acids include HCl, HBr, HBF₄, H₃ PO₄, H₃ PO₃, H₂ SO₄ and HI.Examples of materials capable of generating acidic promoters underhydroxycarbonylation conditions include ammonium and alkyl ammoniumhalides, alkali metal halides, organic acyl halides, andorganosilylhalides. The amount of promoter is generally in the range offrom about 1 to 10 mole equivalents per metal, e.g., palladium.

The particular hydroxycarbonylation reaction conditions are not narrowlycritical and can be any effective hydroxycarbonylation conditionssufficient to produce the unsaturated acids. The reactors may be stirredtanks, tubular reactors and the like. The exact reaction conditions willbe governed by the best compromise between achieving high catalystselectivity, activity, lifetime and ease of operability, as well as theintrinsic reactivity of the alkadienes in question and the stability ofthe alkadienes and the desired reaction product to the reactionconditions. Products may be recovered after a particular reaction andpurified if desired although preferably they are introduced to the nextreaction without purification. Recovery and purification may be by anyappropriate means, which will largely be determined by the particularalkadiene and catalyst employed, and may include distillation, phaseseparation, extraction, absorption, crystallization, derivativeformation and the like. Of course, it is to be understood that thehydroxycarbonylation reaction conditions employed will be governed bythe type of unsaturated acid product desired.

The hydroxycarbonylation process may be conducted at a total gaspressure of carbon monoxide and alkadiene starting compound of fromabout 1 to about 10,000 psia. In general, the hydroxycarbonylationprocess is operated at a total gas pressure of carbon monoxide andalkadiene starting compound of less than about 3000 psia and morepreferably less than about 2000 psia, the minimum total pressure beinglimited predominately by the amount of reactants necessary to obtain adesired rate of reaction. The total pressure of the hydroxycarbonylationprocess will be dependent on the particular catalyst system employed. Itis understood that carbon monoxide can be employed alone, in mixturewith other gases, e.g., hydrogen, or may be produced in situ underreaction conditions.

Further, the hydroxycarbonylation process may be conducted at a reactiontemperature from about 25° C. to about 300° C. In general, ahydroxycarbonylation reaction temperature of about 50° C. to about 200°C. is preferred for all types of alkadiene starting materials. Thetemperature must be sufficient for reaction to occur (which may varywith catalyst system employed), but not so high that ligand or catalystdecomposition occurs. At high temperatures (which may vary with catalystsystem employed), the formation of undesired byproducts, e.g.,vinylcyclohexene, may occur.

The quantity of water used is not narrowly critical. The water:butadienemolar equivalents ratio is generally between about 0.1:1 and 100:1,preferably between about 0.1:1 and 10:1, and more preferably betweenabout 0.5:1 and 2:1. Preferably the molar ratio of water:butadiene isabout 1:1. Water may be fed either batchwise or continuously.

The hydroxycarbonylation reactions may be conducted in the presence ofwater or an organic solvent. The solvent preferably does not react withthe product unsaturated acids and will not itself be hydroxycarbonylatedunder the reaction conditions. Depending on the particular catalyst andreactants employed, suitable organic solvents include, for example,ethers, esters, ketones, aliphatic or aromatic hydrocarbons,fluorocarbons, silicones, polyethers, chlorinated hydrocarbons,carboxylic acids and the like. Any suitable solvent which does notunduly adversely interfere with the intended hydroxycarbonylationreaction can be employed and such solvents may include those disclosedheretofore commonly employed in known metal catalyzedhydroxycarbonylation reactions. Mixtures of one or more differentsolvents may be employed if desired. Illustrative preferred solventsemployable in the production of unsaturated acids include ketones (e.g.acetone, methylethyl ketone and methylisobutyl ketone), esters (e.g.ethyl acetate, methyl acetate and butyrolactone), hydrocarbons (e.g.benzene, toluene and xylene), nitrohydrocarbons (e.g. nitrobenzene),ethers (e.g. diphenyl ether, dioxane, tetrahydrofuran (THF), glyme,anisole, trioxanone and diisopropyl ether), sulfoxides and sulfones suchas dimethyl sulfoxide and diisopropyl sulfone, and sulfolane. The amountof solvent employed is not critical to the subject invention and needonly be that amount sufficient to facilitate the hydroxycarbonylationreaction and solubilize the catalyst and free ligand. In general, theamount of solvent may range from about 5 percent by weight up to about99 percent by weight or more based on the total weight of thehydroxycarbonylation reaction mixture starting material.

In an embodiment of the invention, the hydroxycarbonylation reactionmixture may consist of one or more liquid phases, e.g. a polar and anonpolar phase. Such processes are often advantageous in, for example,separating products from catalyst and/or reactants by partitioning intoeither phase. In addition, product selectivities dependent upon solventproperties may be increased by carrying out the reaction in thatsolvent. An illustrative application of this technology is theaqueous-phase hydroxycarbonylation of olefins employing sulfonatedphosphine ligands for the palladium catalyst. A process carried out inaqueous solvent is particularly advantageous for the preparation ofunsaturated acids because the products may be separated from thecatalyst by extraction into an organic solvent.

As described herein, the phosphorus-containing ligand for thehydroxycarbonylation catalyst may contain any of a number ofsubstituents, such as cationic or anionic substituents, which willrender the catalyst soluble in a polar phase, e.g. water. Optionally, aphase-transfer catalyst may be added to the reaction mixture tofacilitate transport of the catalyst, reactants, or products into thedesired solvent phase. The structure of the ligand or the phase-transfercatalyst is not critical and will depend on the choice of conditions,reaction solvent, and desired products.

When the catalyst is present in a multiphasic system, the catalyst maybe separated from the reactants and/or products by conventional methodssuch as extraction or decantation. The reaction mixture itself mayconsist of one or more phases; alternatively, the multiphasic system maybe created at the end of the reaction by for example addition of asecond solvent to separate the products from the catalyst. See, forexample, U.S. Pat. No. 5,180,854, the disclosure of which isincorporated herein by reference.

The hydroxycarbonylation can be performed in the presence of organicnitrogen containing bases. The addition of these bases can beadvantageous because they improve the catalyst stability. Examples ofaromatic nitrogen containing bases include N-heterocyclic bases, forexample, pyridine, alkylated pyridines, quinoline, lutidine, picoline,isoquinoline, alkylated quinolines and isoquinolines, acridine andN-methyl-2-pyrrolidinone or N,N-dimethylaniline, N,N-diethylaniline,N,N-diethyltoluidine, N,N-dibutyltoluidine, N,N-dimethylformamide,benzimidazole and benzotriazole. The amount of nitrogen containing basemay range from about 0.1:1 or less to about 10:1 or greater based uponthe unsaturated acid or salt.

In an embodiment, the hydroxycarbonylation involves the preparation ofpentenoic acids by hydroxycarbonylation of butadiene as described abovewherein the following procedures are performed:

(a) carbon monoxide, water, a source of metal, e.g., palladium, and anorganophosphorus ligand and optionally a promoter and a solvent arecontinuously brought into a reactor in which the hydroxycarbonylationtakes place;

(b) optionally separating part of the reaction mixture from the reactor;

(c) optionally separating from the separated reaction mixture unreactedcarbon monoxide, unreacted butadiene and unreacted water and returningthese reactants to (a); and

(d) optionally returning the remaining mixture of (c), containing metal,e.g., palladium, and the ligand and optionally the solvent and thepromoter to (a). Preferably a part of the remaining mixture of (c) isseparated from the mixture and led to a drain (purge) in order toprevent a build up of byproducts in the circulating reaction mixture.

Procedure (a) can be performed in several ways, for example, in acontinuously stirred tank reactor or a bubble column in which theproduct is simultaneously stripped from the liquid phase.

Separating the carbon monoxide, butadiene and water from the reactionmixture in (c) can be performed in various ways. Generally the carbonmonoxide is separated first from the reaction mixture in, for example, asimple gas-liquid separation unit. The butadiene and water can beseparated from the reaction mixture in one step. Separation of thevarious compounds can be performed in various ways, for example, bysimple flash evaporation or by distillation. The choice as to which unitoperation is the most suitable will depend on the physical properties ofthe compounds to be separated.

The ratio of the remaining mixture of (c) which is returned to (a) andthe part which is processed to a drain will depend on the amount ofcontaminants (for example, byproducts) allowed in the recirculatingreaction mixture. When a large part will be sent to the drain, a lowdegree of contamination in the recirculating reaction mixture will bethe result and vice versa. The ratio of the remaining mixture of (c)which is returned to (a) and the part which is processed to a drain willdepend on the amount of contamination formed in the hydroxycarbonylationand the acceptable level of contamination in the circulating processstream.

The part which is sent to the drain will contain apart from the abovementioned contaminants also the valuable metals and ligands andoptionally promoter and solvent (provided promoter and solvent are usedin the hydroxycarbonylation). The metals, ligands and solvent may beisolated from this mixture in order to advantageously reuse thesecompounds in the hydroxycarbonylation. Examples of possible processes toseparate these valuable compounds from some of the byproducts is bydistillation, crystallization and extraction.

As indicated above, it may be desirable to carry out thehydroxycarbonylation process of this invention in a continuous manner.In general, continuous hydroxycarbonylation processes may involve: (a)hydroxycarbonylating the alkadiene starting material(s) with carbonmonoxide and water in a liquid homogeneous reaction mixture comprising asolvent and the catalyst; (b) maintaining reaction temperature andpressure conditions favorable to the hydroxycarbonylation of thealkadiene starting material(s); (c) supplying make-up quantities of thealkadiene starting material(s), carbon monoxide and water to thereaction medium as those reactants are used up; and (d) recovering thedesired product(s) in any manner desired. The continuous process can becarried out in a single pass mode, i.e., wherein a mixture comprisingunreacted alkadiene starting material(s) and product is removed from theliquid reaction mixture from whence the product is recovered and make-upalkadiene starting material(s), carbon monoxide and water are suppliedto the liquid reaction medium for the next single pass through withoutrecycling the unreacted alkadiene starting material(s). However, it maybe desirable to employ a continuous process that involves either aliquid and/or gas recycle procedure. Such types of recycle procedure mayinvolve the liquid recycling of the catalyst solution separated from thedesired product or a gas cycle procedure, as well as a combination ofboth a liquid and gas recycle procedure if desired. Illustrative liquidand gas recycle procedures are disclosed in U.S. Pat. Nos. 4,148,830 and4,247,486, the disclosures of which are incorporated herein byreference.

The substituted and unsubstituted unsaturated acids that can be preparedby the hydroxycarbonylation process include, for example, alkenoic acidssuch as cis-3-pentenoic acids, trans-3-pentenoic acids, 4-pentenoicacid, cis-2-pentenoic acids and/or trans-2-pentenoic acids and the like.Illustrative of suitable substituted and unsubstituted unsaturated acidintermediates (including derivatives of substituted or unsubstitutedunsaturated acid intermediates) include those permissible substitutedand unsubstituted unsaturated acids which may be described inKirk-Othmer, Encyclopedia of Chemical Technology, Fourth Edition, 1996,the pertinent portions of which are incorporated herein by reference.The unsaturated acids described herein are useful in a variety ofapplications, such as chemical intermediates and the like.

The subsequent neutralization (optional) and hydroformylation of theunsaturated acid is preferably conducted without the need to separatethe unsaturated acid from the other components of the crude reactionmixtures, e.g., catalysts.

Neutralization Stage or Reaction (Optional)

The neutralization process employed herein involves converting one ormore substituted or unsubstituted unsaturated acids, e.g., pentenoicacids, to one or more substituted or unsubstituted unsaturated acidsalts, e.g., pentenoic acid salts. As used herein, the term"neutralization" is contemplated to include, but is not limited to, allpermissible neutralization processes which involve converting one ormore substituted or unsubstituted unsaturated acids to one or moresubstituted or unsubstituted unsaturated acid salts. It is understoodthat neutralization may be conducted during the hydroxycarbonylationstage. In general, the neutralization stage comprises reacting one ormore substituted or unsubstituted unsaturated acids with a base toproduce one or more substituted or unsubstituted unsaturated acid salts.

In particular, one or more substituted or unsubstituted pentenoic acidscan be reacted with a base to produce one or more substituted orunsubstituted pentenoic acid salts. For example, 3-pentenoic acid can bereacted with triethylamine to produce triethylammonium 3-pentenoate orwith ammonia to produce ammonium 3-pentenoate. The neutralization ofunsaturated acids to unsaturated acid salts may be carried out byconventional methods.

Unsaturated acids useful in the neutralization processes are knownmaterials and can be prepared by the hydroxycarbonylation processdescribed above. Reaction mixtures comprising unsaturated acids may beuseful herein. The amount of unsaturated acids employed in theneutralization stage or reaction is not narrowly critical and can be anyamount sufficient to produce pentenoic acid salts, preferably in highselectivities.

The base useful in the reaction of a pentenoic acid to a pentenoic acidsalt is not narrowly critical. Illustrative bases include, for example,nitrogen containing bases (e.g., ammonia, trimethylamine, triethylamine,trioctylamine, ethyldioctylamine, tribenzylamine, diethylphenylamine,diphenylmethylamine, dimethylamine, diethanolamine, pyridine,bipyridine, benzimidazole, benzotriazole, ethylenediamine, andtetramethylethylenediamine), alkali metal hydroxides, alkoxides,carboxylates, carbonates and phosphates (e.g., sodium hydroxide,potassium hydroxide, lithium hydroxide, sodium methoxide, lithiumbutoxide, sodium carbonate, and potassium phosphate), ammonium or alkylammonium hydroxides and carboxylates (e.g. ammonium hydroxide,trimethylbutylammonium hydroxide, tetrabutylammonium hydroxide,trimethylbenzylammonium hydroxide, triethylphenylammonium acetate, andtetraethylammonium benzoate) alkyl phosphonium hydroxides andcarboxylates, (e.g. octyltrimethylphosphonium hydroxide,tetrabutylphosponium hydroxide, ethyltriphenylphosphonium hydroxide,trimethylbenzylphosponium hydroxide), bis(hydrocarbyl-phosphine)iminiumhydroxides, (e.g., bis(triphenylphosphine)iminium hydroxide,bis(tribenzylphosphine)iminium hydroxide). Alternatively, the base usedfor neutralization of the pentenoic acid may be incorporated into theligand structure (e.g. tris(dimethylaminophenyl)-phosphine,bis(dimethylaminoethyl)phenylphosphine), either as the metal-ligandcomplex catalyst or as free ligand. The amount of base employed shouldbe sufficient to neutralize, at least in part, the unsaturated acids.

The reactors and reaction conditions for the neutralization reaction areknown in the art. The particular neutralization reaction conditions arenot narrowly critical and can be any effective neutralization conditionssufficient to produce one or more unsaturated acid salts. The reactorsmay be stirred tanks, tubular reactors and the like. The exact reactionconditions will be governed by the best compromise between achievinghigh selectivity and ease of operability, as well as the intrinsicreactivity of the starting materials in question and the stability ofthe starting materials and the desired reaction product to the reactionconditions.

The particular neutralization reaction conditions are not narrowlycritical and can be any effective neutralization procedures sufficientto produce one or more unsaturated acid salts. For the reaction ofunsaturated acids with a base, the temperature must be sufficient forreaction to occur but not so high that the unsaturated acids undergoundesirable side reactions, i.e., a temperature of from about 0° C. toabout 200° C., preferably about 20° C. to about 100° C.

Illustrative substituted and unsubstituted unsaturated acid salts thatcan be prepared by the neutralization processes include one or more ofthe following: alkenoic acid salts such as triethylammonium3-pentenoate, ammonium 3-pentenoate, octyltriethylammonium 3-pentenoate,including mixtures comprising one or more unsaturated acid salts.Illustrative of suitable substituted and unsubstituted unsaturated acidsalts include those permissible substituted and unsubstitutedunsaturated acid salts which are described in Kirk-Othmer, Encyclopediaof Chemical Technology, Fourth Edition, 1996, the pertinent portions ofwhich are incorporated herein by reference.

The subsequent hydroformylation of the unsaturated acid salt ispreferably conducted without the need to separate the unsaturated acidsalt from the other components of the crude reaction mixtures, e.g.,catalysts.

Hydroformylation Stage or Reaction

The hydroformylation process involves the production of aldehyde acidsor salts, e.g., formylvaleric acid or salts, and/or one or moresubstituted or unsubstituted epsilon caprolactam precursors by reactingan unsaturated acid or salt, e.g., pentenoic acid or salt, with carbonmonoxide and hydrogen in the presence of a solubilized metal-ligandcomplex catalyst and free ligand in a liquid medium that also contains asolvent for the catalyst and ligand. The processes may be carried out ina continuous single pass mode in a continuous gas recycle manner or morepreferably in a continuous liquid catalyst recycle manner as describedbelow. The hydroformylation processing techniques employable herein maycorrespond to any known processing techniques such as preferablyemployed in conventional liquid catalyst recycle hydroformylationreactions. As used herein, the term "hydroformylation" is contemplatedto include, but is not limited to, all permissible hydroformylationprocesses which involve converting one or more substituted orunsubstituted unsaturated acids or salts to one or more substituted orunsubstituted aldehyde acids or salts and/or one or more substituted orunsubstituted epsilon caprolactam precursors. In general, thehydroformylation stage or reaction comprises reacting one or moresubstituted or unsubstituted unsaturated acids or salts with carbonmonoxide and hydrogen in the presence of a catalyst to produce one ormore substituted or unsubstituted aldehyde acids or salts. As usedherein, substituted or unsubstituted epsilon caprolactam precursors iscontemplated to include, but are not limited to, one or more offormylvaleric acid and/or salts thereof, iminocaproic acid and/or saltsthereof, aminocaproic acid and/or salts thereof, caprolactam,caprolactone, imines, hemiaminals, imides, amides or amines derived fromformylvaleric acid and its salts, and the corresponding dimers, trimersand oligomers or salts thereof.

The hydroformylation reaction mixtures employable herein includes anysolution derived from any corresponding hydroformylation process thatmay contain at least some amount of four different main ingredients orcomponents, i.e., the aldehyde acid or salt product and/or epsiloncaprolactam precursors, a metal-ligand complex catalyst, optionally freeligand and an organic solubilizing agent for said catalyst and said freeligand, said ingredients corresponding to those employed and/or producedby the hydroformylation process from whence the hydroformylationreaction mixture starting material may be derived. By "free ligand" ismeant ligand that is not complexed with (tied to or bound to) the metal,e.g., rhodium atom, of the complex catalyst. It is to be understood thatthe hydroformylation reaction mixture compositions employable herein canand normally will contain minor amounts of additional ingredients suchas those which have either been deliberately employed in thehydroformylation process or formed in situ during said process. Examplesof such ingredients that can also be present include unreacted olefinsalt starting material, carbon monoxide and hydrogen gases, and in situformed type products, such as saturated hydrocarbons and/or unreactedisomerized olefins corresponding to the unsaturated acid salt startingmaterials, and high boiling liquid condensation byproducts, as well asother inert co-solvent type materials or hydrocarbon additives, ifemployed.

The catalysts useful in the hydroformylation process includemetal-ligand complex catalysts. The permissible metals which make up themetal-ligand complexes include Group 8, 9 and 10 metals selected fromrhodium (Rh), cobalt (Co), iridium (Ir), ruthenium (Ru), iron (Fe),nickel (Ni), palladium (Pd), platinum (Pt), osmium (Os) and mixturesthereof, with the preferred metals being rhodium, cobalt, iridium andruthenium, more preferably rhodium, cobalt and ruthenium, especiallyrhodium. The permissible ligands include, for example, organophosphorus,organoarsenic and organoantimony ligands, or mixtures thereof,preferably organophosphorus ligands. The permissible organophosphorusligands which make up the metal-ligand complexes includeorganophosphines, e.g., mono-, di-, tri- and poly-(organophosphines),and organophosphites, e.g., mono-, di-, tri- andpoly-(organophosphites). Other permissible organophosphorus ligandsinclude, for example, organophosphonites, organophosphinites, aminophosphines and the like. Still other permissible ligands include, forexample, heteroatom-containing ligands such as described in U.S. patentapplication Ser. No. (08/818,781), filed Mar. 10, 1997, the disclosureof which is incorporated herein by reference. Mixtures of such ligandsmay be employed if desired in the metal-ligand complex catalyst and/orfree ligand and such mixtures may be the same or different. Thisinvention is not intended to be limited in any manner by the permissibleorganophosphorus ligands or mixtures thereof. In an embodiment, theligands useful in the hydroxycarbonylation and hydroformylationreactions may be the same or different. It is to be noted that thesuccessful practice of this invention does not depend and is notpredicated on the exact structure of the metal-ligand complex species,which may be present in their mononuclear, dinuclear and/or highernuclearity forms. Indeed, the exact structure is not known. Although itis not intended herein to be bound to any theory or mechanisticdiscourse, it appears that the catalytic species may in its simplestform consist essentially of the metal in complex combination with theligand and carbon monoxide when used.

The term "complex" as used herein and in the claims means a coordinationcompound formed by the union of one or more electronically richmolecules or atoms capable of independent existence with one or moreelectronically poor molecules or atoms, each of which is also capable ofindependent existence. For example, the ligands employable herein, i.e.,organophosphorus ligands, may possess one or more phosphorus donoratoms, each having one available or unshared pair of electrons which areeach capable of forming a coordinate covalent bond independently orpossibly in concert (e.g., via chelation) with the metal. Carbonmonoxide (which is also properly classified as a ligand) can also bepresent and complexed with the metal. The ultimate composition of thecomplex catalyst may also contain an additional ligand, e.g., hydrogenor an anion satisfying the coordination sites or nuclear charge of themetal. Illustrative additional ligands include, e.g., halogen (Cl, Br,I), alkyl, aryl, substituted aryl, acyl, CF₃, C₂ F₅, CN, (R)₂ PO andRP(O)(OH)O (wherein each R is the same or different and is a substitutedor unsubstituted hydrocarbon radical, e.g., the alkyl or aryl), acetate,pentenoate, acetylacetonate, SO₄, BF₄, PF₆, NO₂, NO₃, CH₃ O, CH₂ ═CHCH₂,CH₂ ═CHCH₂ CH₃, CH₃ CH═CHCH₂, C₆ H₅ CN, CH₃ CN, NO, NH₃, pyridine, (C₂H₅)₃ N, mono-olefins, diolefins and triolefins, tetrahydrofuran, and thelike. It is of course to be understood that the complex species arepreferably free of any additional organic ligand or anion that mightpoison the catalyst and have an undue adverse effect on catalystperformance. Preferred metal-ligand complex catalysts includerhodium-organophosphine ligand complex catalysts andrhodium-organophosphite ligand complex catalysts.

The number of available coordination sites on such metals is well knownin the art. Thus the catalytic species may comprise a complex catalystmixture, in their monomeric, dimeric or higher nuclearity forms, whichare preferably characterized by at least one phosphorus-containingmolecule complexed per metal, e.g., rhodium. As noted above, it isconsidered that the catalytic species of the preferred catalyst employedin the hydroformylation reaction may be complexed with carbon monoxideand hydrogen in addition to the organophosphorus ligands in view of thecarbon monoxide and hydrogen gas employed by the hydroformylationreaction.

Among the organophosphines that may serve as the ligand of themetal-organophosphine complex catalyst and/or free organophosphineligand of the hydroformylation reaction mixture starting materials aretriorganophosphines, trialkylphosphines, alkyldiarylphosphines,dialkylarylphosphines, dicycloalkylarylphosphines,cycloalkyldiarylphosphines, triaralkylphosphines,tricycloalkylphosphines, and triarylphosphines, alkyl and/or aryldiphosphines and bisphosphine mono oxides, as well as ionictriorganophosphines containing at least one ionic moiety selected fromthe salts of sulfonic acid, of carboxylic acid, of phosphonic acid andof quaternary ammonium compounds, and the like. Of course any of thehydrocarbon radicals of such tertiary non-ionic and ionicorganophosphines may be substituted if desired, with any suitablesubstituent that does not unduly adversely affect the desired result ofthe hydroformylation reaction. The organophosphine ligands employable inthe hydroformylation reaction and/or methods for their preparation areknown in the art.

Illustrative triorganophosphine ligands may be represented by theformula: ##STR2## wherein each R¹ is the same or different and is asubstituted or unsubstituted monovalent hydrocarbon radical, e.g., analkyl or aryl radical. Suitable hydrocarbon radicals may contain from 1to 24 carbon atoms or greater. Illustrative substituent groups that maybe present on the aryl radicals include, e.g., alkyl radicals, alkoxyradicals, silyl radicals such as --Si(R²)₃ ; amino radicals suchas--N(R²)₂ ; acyl radicals such as --C(O)R² ; carboxy radicals suchas--C(O)OR² ; acyloxy radicals such as --OC(O)R² ; amido radicals suchas --C(O)N(R²)₂ and --N(R²)C(O)R² ; ionic radicals such as --SO₃ Mwherein M represents inorganic or organic cationic atoms or radicals;sulfonyl radicals such as --SO₂ R² ; ether radicals such as --OR² ;sulfinyl radicals such as --SOR² ; sulfenyl radicals such as --Sr² aswell as halogen, nitro, cyano, trifluoromethyl and hydroxy radicals, andthe like, wherein each R² individually represents the same or differentsubstituted or unsubstituted monovalent hydrocarbon radical, with theproviso that in amino substituents such as --N(R²)₂, each R² takentogether can also represent a divalent bridging group that forms aheterocyclic radical with the nitrogen atom and in amido substituentssuch as C(O)N(R²)₂ and --N(R²)C(O)R² each --R² bonded to N can also behydrogen. Illustrative alkyl radicals include, e.g., methyl, ethyl,propyl, butyl and the like. Illustrative aryl radicals include, e.g.,phenyl, naphthyl, diphenyl, fluorophenyl, difluorophenyl,benzoyloxyphenyl, carboethoxyphenyl, acetylphenyl, ethoxyphenyl,phenoxyphenyl, hydroxyphenyl; carboxyphenyl, trifluoromethylphenyl,methoxyethylphenyl, acetamidophenyl, dimethylcarbamylphenyl, tolyl,xylyl, and the like.

Illustrative specific organophosphines include, e.g.,triphenylphosphine, tris-p-tolyl phosphine,tris-p-methoxyphenylphosphine, tris-p-fluorophenylphosphine,tris-p-chlorophenylphosphine, tris-dimethylaminophenylphosphine,propyldiphenylphosphine, t-butyldiphenylphosphine,n-butyldiphenylphosphine, n-hexyldiphenylphosphine,cyclohexyldiphenylphosphine, dicyclohexylphenylphosphine,tricyclohexylphosphine, tribenzylphosphine, DIOP, i.e.,(4R,5R)-(-)-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butaneand/or(4S,5S)-(+)-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butaneand/or(4S,5R)-(-)-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane,substituted or unsubstituted bicyclic bisphosphines such as1,2-bis(1,4-cyclooctylenephosphino)ethane,1,3-bis(1,4-cyclooctylenephosphino)propane,1,3-bis(1,5-cyclooctylenephosphino)propane and1,2-bis(2,6-dimethyl-1,4-cyclooctylenephosphino)ethane, substituted orunsubstituted bis(2,2'-diphenylphosphinomethyl)biphenyl such asbis(2,2'-diphenylphosphinomethyl)biphenyl andbis{2,2'-di(4-fluorophenyl)phosphinomethyl}biphenyl, xantphos,thixantphos, bis(diphenylphosphino)ferrocene,bis(diisopropylphosphino)ferrocene, bis(diphenylphosphino)ruthenocene,as well as the alkali and alkaline earth metal salts of sulfonatedtriphenylphosphines, e.g., of (tri-m-sulfophenyl)phosphine and of(m-sulfophenyl)diphenyl-phosphine and the like.

More particularly, illustrative metal-organophosphine complex catalystsand illustrative free organophosphine ligands include, e.g., thosedisclosed in U.S. Pat. Nos. 3,527,809; 4,148,830; 4,247,486; 4,283,562;4,400,548; 4,482,749, 4,861,918; 4,694,109; 4,742,178; 4,851,581;4,824,977; 5,332,846; 4,774,362; and WO Patent Application No. 95/30680,published Nov. 16, 1995; the disclosures of which are incorporatedherein by reference.

The organophosphites that may serve as the ligand of themetal-organophosphite ligand complex catalyst and/or free ligand of theprocesses and reaction product mixtures of this invention may be of theachiral (optically inactive) or chiral (optically active) type and arewell known in the art.

Among the organophosphites that may serve as the ligand of themetal-organophosphite complex catalyst and/or free organophosphiteligand of the hydroformylation reaction mixture starting materials aremonoorganophosphites, diorganophosphites, triorganophosphites andorganopolyphosphites. The organophosphite ligands employable in thisinvention and/or methods for their preparation are known in the art.

Representative monoorganophosphites may include those having theformula: ##STR3## wherein R³ represents a substituted or unsubstitutedtrivalent hydrocarbon radical containing from 4 to 40 carbon atoms orgreater, such as trivalent acyclic and trivalent cyclic radicals, e.g.,trivalent alkylene radicals such as those derived from1,2,2-trimethylolpropane and the like, or trivalent cycloalkyleneradicals such as those derived from 1,3,5-trihydroxycyclohexane, and thelike. Such monoorganophosphites may be found described in greaterdetail, e.g., in U.S. Pat. No. 4,567,306, the disclosure of which isincorporated herein by reference.

Representative diorganophosphites may include those having the formula:##STR4## wherein R⁴ represents a substituted or unsubstituted divalenthydrocarbon radical containing from 4 to 40 carbon atoms or greater andW represents a substituted or unsubstituted monovalent hydrocarbonradical containing from 1 to 18 carbon atoms or greater.

Representative substituted and unsubstituted monovalent hydrocarbonradicals represented by W in the above formula (III) include alkyl andaryl radicals, while representative substituted and unsubstituteddivalent hydrocarbon radicals represented by R⁴ include divalent acyclicradicals and divalent aromatic radicals. Illustrative divalent acyclicradicals include, e.g., alkylene, alkylene-oxy-alkylene,alkylene-NX-alkylene wherein X is hydrogen or a substituted orunsubstituted monovalent hydrocarbon radical, alkylene-S-alkylene, andcycloalkylene radicals, and the like. The more preferred divalentacyclic radicals are the divalent alkylene radicals such as disclosedmore fully, e.g., in U.S. Pat. Nos. 3,415,906 and 4,567,302 and thelike, the disclosures of which are incorporated herein by reference.Illustrative divalent aromatic radicals include, e.g., arylene,bisarylene, arylene-alkylene, arylene-alkylene-arylene,arylene-oxy-arylene, arylene-NX-arylene wherein X is as defined above,arylene-S-arylene, and arylene-S-alkylene, and the like. More preferablyR⁴ is a divalent aromatic radical such as disclosed more fully, e.g., inU.S. Pat. Nos. 4,599,206 and 4,717,775, and the like, the disclosures ofwhich are incorporated herein by reference.

Representative of a more preferred class of diorganophosphites are thoseof the formula: ##STR5## wherein W is as defined above, each Ar is thesame or different and represents a substituted or unsubstituted arylradical, each y is the same or different and is a value of 0 or 1, Qrepresents a divalent bridging group selected from --C(R⁵)₂ --, --O--,--S--, --NR⁶⁻, Si(R⁷)₂ -- and --CO--, wherein each R⁵ is the same ordifferent and represents hydrogen, alkyl radicals having from 1 to 12carbon atoms, phenyl, tolyl, and anisyl, R⁶ represents hydrogen or amethyl radical, each R⁷ is the same or different and represents hydrogenor a methyl radical, and m is a value of 0 or 1. Such diorganophosphitesare described in greater detail, e.g., in U.S. Pat. Nos. 4,599,206 and4,717,775, the disclosures of which are incorporated herein byreference.

Representative triorganophosphites may include those having the formula:##STR6## wherein each R⁸ is the same or different and is a substitutedor unsubstituted monovalent hydrocarbon radical, e.g., an alkyl or arylradical. Suitable hydrocarbon radicals may contain from 1 to 24 carbonatoms or greater and may include those described above for R¹ in formula(I).

Representative organopolyphosphites contain two or more tertiary(trivalent) phosphorus atoms and may include those having the formula:##STR7## wherein X¹ represents a substituted or unsubstituted n-valenthydrocarbon bridging radical containing from 2 to 40 carbon atoms, eachR⁹ is the same or different and is a divalent hydrocarbon radicalcontaining from 4 to 40 carbon atoms, each R¹⁰ is the same or differentand is a substituted or unsubstituted monovalent hydrocarbon radicalcontaining from 1 to 24 carbon atoms, a and b can be the same ordifferent and each have a value of 0 to 6, with the proviso that the sumof a+b is 2 to 6 and n equals a+b. Of course it is to be understood thatwhen a has a value of 2 or more, each R⁹ radical may be the same ordifferent, and when b has a value of 1 or more, each R¹⁰ radical mayalso be the same or different.

Representative n-valent (preferably divalent) hydrocarbon bridgingradicals represented by X¹, as well as representative divalenthydrocarbon radicals represented by R⁹ above, include both acyclicradicals and aromatic radicals, such as alkylene, alkylene--Q_(m)--alkylene, cycloalkylene, arylene, bisarylene, arylene-alkylene, andarylene-(CH₂)y--Q_(m) --(CH₂)y-arylene radicals, and the like, whereinQ, m and y are as defined above for formula (IV). The more preferredacyclic radicals represented by X¹ and R⁹ above are divalent alkyleneradicals, while the more preferred aromatic radicals represented by X¹and R⁹ above are divalent arylene and bisarylene radicals, such asdisclosed more fully, e.g., in U.S. Pat. Nos. 3,415,906; 4,567,306;4,599,206; 4,769,498; 4,717,775; 4,885,401; 5,202,297; 5,264,616 and5,364,950, and the like, the disclosures of which are incorporatedherein by reference. Representative monovalent hydrocarbon radicalsrepresented by each R¹⁰ radical above include alkyl and aromaticradicals.

Illustrative preferred organopolyphosphites may include bisphosphitessuch as those of formulas (VII) to (IX) below: ##STR8## wherein each R⁹,R¹⁰ and X¹ of formulas (VII) to (IX) are the same as defined above forformula (VI). Preferably, each R⁹ and X¹ represents a divalenthydrocarbon radical selected from alkylene, arylene,arylene-alkylene-arylene, and bisarylene, while each R¹⁰ represents amonovalent hydrocarbon radical selected from alkyl and aryl radicals.Phosphite ligands of such formulas (VI) to (IX) may be found disclosed,e.g., in said U.S. Pat. Nos. 4,668,651; 4,748,261; 4,769,498; 4,885,401;5,202,297; 5,235,113; 5,254,741; 5,264,616; 5,312,996; 5,364,950; and5,391,801; the disclosures of all of which are incorporated herein byreference.

Representative of more preferred classes of organobisphosphites arethose of the following formulas (X) to (XII): ##STR9## wherein Ar, Q,R⁹, R¹⁰, X¹, m and y are as defined above. Most preferably X¹ representsa divalent aryl-(CH₂)_(y) --(Q)_(m) --(CH₂)_(y) -aryl radical whereineach y individually has a value of 0 or 1; m has a value of 0 or 1 and Qis --O--, --S-- or --C(R⁵)₂ -- wherein each R⁵ is the same or differentand represents a hydrogen or methyl radical. More preferably each alkylradical of the above defined R¹⁰ groups may contain from 1 to 24 carbonatoms and each aryl radical of the above-defined Ar, X¹, R⁹ and R¹⁰groups of the above formulas (VI) to (XII) may contain from 6 to 18carbon atoms and said radicals may be the same or different, while thepreferred alkylene radicals of X¹ may contain from 2 to 18 carbon atomsand the preferred alkylene radicals of R⁹ may contain from 5 to 18carbon atoms. In addition, preferably the divalent Ar radicals anddivalent aryl radicals of X¹ of the above formulas are phenyleneradicals in which the bridging group represented by --(CH₂)_(y)--(Q)_(m) --(CH₂)_(y) -- is bonded to said phenylene radicals inpositions that are ortho to the oxygen atoms of the formulas thatconnect the phenylene radicals to their phosphorus atom of the formulas.It is also preferred that any substituent radical when present on suchphenylene radicals be bonded in the para and/or ortho position of thephenylene radicals in relation to the oxygen atom that bonds the givensubstituted phenylene radical to its phosphorus atom.

Moreover, if desired any given organophosphite in the above formulas(VI) to (XII) may be an ionic phosphite, i.e., may contain one or moreionic moieties selected from the group consisting of:

--SO₃ M wherein M represents an inorganic or organic cation,

--PO₃ M wherein M represents an inorganic or organic cation,

--N(R¹¹)₃ X² wherein each R¹¹ is the same or different and represents ahydrocarbon radical containing from 1 to 30 carbon atoms, e.g, alkyl,aryl, alkaryl, aralkyl, and cycloalkyl radicals, and X² represents aninorganic or organic anion,

--CO₂ M wherein M represents an inorganic or organic cation,

as described, e.g., in U.S. Pat. Nos. 5,059,710; 5,113,022, 5,114,473and 5,449,653, the disclosures of which are incorporated herein byreference. Thus, if desired, such phosphite ligands may contain from 1to 3 such ionic moieties, while it is preferred that only one such ionicmoiety be substituted on any given aryl moiety in the phosphite ligandwhen the ligand contains more than one such ionic moiety. As suitablecounter-ions, M and X², for the anionic moieties of the ionic phosphitesthere can be mentioned hydrogen (i.e. a proton), the cations of thealkali and alkaline earth metals, e.g., lithium, sodium, potassium,cesium, rubidium, calcium, barium, magnesium and strontium, the ammoniumcation, quaternary ammonium cations, phosphonium cations, arsoniumcations and iminium cations. Suitable anionic atoms or radicals include,for example, sulfate, carbonate, phosphate, chloride, acetate, oxalateand the like.

Of course any of the R⁹, R¹⁰, X² and Ar radicals of such non-ionic andionic organophosphites of formulas (VI) to (XII) above may besubstituted if desired, with any suitable substituent containing from 1to 30 carbon atoms that does not unduly adversely affect the desiredresult of the hydroformylation reaction. Substituents that may be onsaid radicals in addition of course to corresponding hydrocarbonradicals such as alkyl, aryl, aralkyl, alkaryl and cyclohexylsubstituents, may include for example silyl radicals such as --Si(R¹²)₃; amino radicals such as --N(R¹²)₂ ; phosphine radicals such as-aryl-P(R¹²)₂ ; acyl radicals such as --C(O)R¹² ; acyloxy radicals suchas --OC(O)R¹² ; amido radicals such as --CON(R¹²)₂ and --N(R¹²)COR¹² ;sulfonyl radicals such as --SO₂ R¹² ; alkoxy radicals such as --OR¹² ;sulfinyl radicals such as --SOR¹² ; sulfenyl radicals such as --SR¹² ;phosphonyl radicals such as --P(O)(R¹²)₂ ; as well as, halogen, nitro,cyano, trifluoromethyl, hydroxy radicals, and the like, wherein each R₁₂radical is the same or different and represents a monovalent hydrocarbonradical having from 1 to 18 carbon atoms (e.g., alkyl, aryl, aralkyl,alkaryl and cyclohexyl radicals), with the proviso that in aminosubstituents such as --N(R¹²)₂ each R¹² taken together can alsorepresent a divalent bridging group that forms a heterocyclic radicalwith the nitrogen atom, and in amido substituents such as --C(O)N(R¹²)₂and --N(R¹²)COR¹² each R¹² bonded to N can also be hydrogen. Of courseit is to be understood that any of the substituted or unsubstitutedhydrocarbon radicals groups that make up a particular givenorganophosphite may be the same or different.

More specifically illustrative substituents include primary, secondaryand tertiary alkyl radicals such as methyl, ethyl, n-propyl, isopropyl,butyl, sec-butyl, t-butyl, neo-pentyl, n-hexyl, amyl, sec-amyl, t-amyl,iso-octyl, decyl, octadecyl, and the like; aryl radicals such as phenyl,naphthyl and the like; aralkyl radicals such as benzyl, phenylethyl,triphenylmethyl, and the like; alkaryl radicals such as tolyl, xylyl,and the like; alicyclic radicals such as cyclopentyl, cyclohexyl,1-methylcyclohexyl, cyclooctyl, cyclohexylethyl, and the like; alkoxyradicals such as methoxy, ethoxy, propoxy, t-butoxy, --OCH₂ CH₂ OCH₃,--(OCH₂ CH₂)₂ OCH₃, --(OCH₂ CH₂)₃ OCH₃, and the like; aryloxy radicalssuch as phenoxy and the like; as well as silyl radicals such as--Si(CH₃)₃, --Si(OCH₃)₃, --Si(C₃ H₇)₃, and the like; amino radicals suchas --NH₂, --N(CH₃)₂, --NHCH₃, --NH(C₂ H₅), and the like; arylphosphineradicals such as --P(C₆ H₅)₂, and the like; acyl radicals such as--C(O)CH₃, --C(O)C₂ H₅, --C(O)C₆ H₅, and the like; carbonyloxy radicalssuch as --C(O)OCH₃ and the like; oxycarbonyl radicals such as --O(CO)C₆H₅, and the like; amido radicals such as --CONH₂, --CON(CH₃)₂,--NHC(O)CH₃, and the like; sulfonyl radicals such as --S(O)₂ C₂ H₅ andthe like; sulfinyl radicals such as --S(O)CH₃ and the like; sulfenylradicals such as --SCH₃, --SC₂ H₅, --SC₆ H₅, and the like; phosphonylradicals such as --P(O)(C₆ H₅)₂, --P(O)(CH₃)₂, --P(O)(C₂ H₅)₂, --P(O)(C₃H₇)₂, --P(O)(C₄ H₉)₂, --P(O)(C₆ H₁₃)₂, --P(O)CH₃ (C₆ H₅), --P(O)(H)(C₆H₅), and the like.

Specific illustrative examples of such organophosphite ligands includethe following:

2-t-butyl-4-methoxyphenyl(3,3'-di-t-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)phosphitehaving the formula: ##STR10##

Still other illustrative organophosphorus ligands useful in thisinvention include those disclosed in U.S. patent application Ser. No.(08/843,389), filed on an even date herewith, the disclosure of which isincorporated herein by reference.

The metal-ligand complex catalysts employable in this invention may beformed by methods known in the art. The metal-ligand complex catalystsmay be in homogeneous or heterogeneous form. For instance, preformedmetal hydrido-carbonyl-organophosphorus ligand catalysts may be preparedand introduced into the reaction mixture of a hydroformylation process.More preferably, the metal-ligand complex catalysts can be derived froma metal catalyst precursor which may be introduced into the reactionmedium for in situ formation of the active catalyst. For example,rhodium catalyst precursors such as rhodium dicarbonyl acetylacetonate,Rh₂ O₃, Rh₄ (CO)₁₂, Rh₆ (CO)₁₆, Rh(NO₃)₃ and the like may be introducedinto the reaction mixture along with the organophosphorus ligand for thein situ formation of the active catalyst. In a preferred embodiment ofthis invention, rhodium dicarbonyl acetylacetonate is employed as arhodium precursor and reacted in the presence of a solvent with theorganophosphorus ligand to form a catalytic rhodium-organophosphorusligand complex precursor which is introduced into the reactor along withexcess free organophosphorus ligand for the in situ formation of theactive catalyst. In any event, it is sufficient for the purpose of thisinvention that carbon monoxide, hydrogen and organophosphorus compoundare all ligands that are capable of being complexed with the metal andthat an active metal-ligand catalyst is present in the reaction mixtureunder the conditions used in the hydroformylation reaction.

More particularly, a catalyst precursor composition can be formedconsisting essentially of a solubilized metal-organophosphorus ligandcomplex precursor catalyst, an organic solvent and free organophosphorusligand. Such precursor compositions may be prepared by forming asolution of a metal starting material, such as a metal oxide, hydride,carbonyl or salt, e.g. a nitrate, which may or may not be in complexcombination with a ligand as defined herein. Any suitable metal startingmaterial may be employed, e.g. rhodium dicarbonyl acetylacetonate, Rh₂O₃, Rh₄ (CO)₁₂, Rh₆ (CO)₁₆, Rh(NO₃)₃, and organophosphorus ligandrhodium carbonyl hydrides. Carbonyl and organophosphorus ligands, if notalready complexed with the initial metal, may be complexed to the metaleither prior to or in situ during the hydroformylation process.

By way of illustration, the preferred catalyst precursor composition ofthis invention consists essentially of a solubilized rhodium carbonylorganophosphorus ligand complex precursor catalyst, a solvent and freeorganophosphorus ligand prepared by forming a solution of rhodiumdicarbonyl acetylacetonate, an organic solvent and a ligand as definedherein. The organophosphorus ligand readily replaces one of the carbonylligands of the rhodium acetylacetonate complex precursor at roomtemperature as witnessed by the evolution of carbon monoxide gas. Thissubstitution reaction may be facilitated by heating the solution ifdesired. Any suitable organic solvent in which both the rhodiumdicarbonyl acetylacetonate complex precursor and rhodiumorganophosphorus ligand complex precursor are soluble can be employed.The amounts of rhodium complex catalyst precursor, organic solvent andorganophosphorus ligand, as well as their preferred embodiments presentin such catalyst precursor compositions may obviously correspond tothose amounts employable in the hydroformylation process of thisinvention. Experience has shown that the acetylacetonate ligand of theprecursor catalyst is replaced after the hydroformylation process hasbegun with a different ligand, e.g., hydrogen, carbon monoxide ororganophosphorus ligand, to form the active complex catalyst asexplained above. In a continuous process, the acetylacetone which isfreed from the precursor catalyst under hydroformylation conditions isremoved from the reaction medium with the product aldehyde acid salt andthus is in no way detrimental to the hydroformylation process. The useof such preferred rhodium complex catalytic precursor compositionsprovides a simple economical and efficient method for handling therhodium precursor metal and hydroformylation start-up.

Accordingly, the metal-ligand complex catalysts used in the process ofthis invention consists essentially of the metal complexed with carbonmonoxide and a ligand, said ligand being bonded (complexed) to the metalin a chelated and/or non-chelated fashion. Moreover, the terminology"consists essentially of", as used herein, does not exclude, but ratherincludes, hydrogen complexed with the metal, in addition to carbonmonoxide and the ligand. Further, such terminology does not exclude thepossibility of other organic ligands and/or anions that might also becomplexed with the metal. Materials in amounts which unduly adverselypoison or unduly deactivate the catalyst are not desirable and so thecatalyst most desirably is free of contaminants. The hydrogen and/orcarbonyl ligands of an active metal-ligand complex catalyst may bepresent as a result of being ligands bound to a precursor catalystand/or as a result of in situ formation, e.g., due to the hydrogen andcarbon monoxide gases employed in hydroformylation process of thisinvention.

As noted the hydroformylation reactions involve the use of ametal-ligand complex catalyst as described herein. Of course mixtures ofsuch catalysts can also be employed if desired. The amount ofmetal-ligand complex catalyst present in the reaction medium of a givenhydroformylation reaction need only be that minimum amount necessary toprovide the given metal concentration desired to be employed and whichwill furnish the basis for at least the catalytic amount of metalnecessary to catalyze the particular hydroformylation reaction involvedsuch as disclosed e.g. in the above-mentioned patents. In general, thecatalyst concentration can range from several parts per million toseveral percent by weight. Organophosphorus ligands can be employed inthe above-mentioned catalysts in a molar ratio of generally from about0.5:1 or less to about 1000:1 or greater. The catalyst concentrationwill be dependent on the hydroformylation reaction conditions andsolvent employed.

In general, the organophosphorus ligand concentration inhydroformylation reaction mixtures may range from between about 0.005and 25 weight percent based on the total weight of the reaction mixture.Preferably the ligand concentration is between 0.01 and 15 weightpercent, and more preferably is between about 0.05 and 10 weight percenton that basis.

In general, the concentration of the metal in the hydroformylationreaction mixtures may be as high as about 2000 parts per million byweight or greater based on the weight of the reaction mixture.Preferably the metal concentration is between about 50 and 1000 partsper million by weight based on the weight of the reaction mixture, andmore preferably is between about 70 and 800 parts per million by weightbased on the weight of the reaction mixture.

In addition to the metal-ligand complex catalyst, free ligand (i.e.,ligand that is not complexed with the metal) may also be present in thehydroformylation reaction medium. The free ligand may correspond to anyof the above-defined phosphorus-containing ligands discussed above asemployable herein. It is preferred that the free organophosphorus ligandbe the same as the phosphorus-containing ligand of themetal-organophosphorus complex catalyst employed. However, such ligandsneed not be the same in any given process. The hydroformylation reactionmay involve up to 100 moles, or higher, of free ligand per mole of metalin the hydroformylation reaction medium. Preferably the hydroformylationreaction is carried out in the presence of from about 0.25 to about 50moles of coordinatable phosphorus, and more preferably from about 0.5 toabout 30 moles of coordinatable phosphorus per mole of metal present inthe reaction medium; said amounts of coordinatable phosphorus being thesum of both the amount of coordinatable phosphorus that is bound(complexed) to the metal present and the amount of free (non-complexed)coordinatable phosphorus present. Of course, if desired, make-up oradditional coordinatable phosphorus can be supplied to the reactionmedium of the hydroformylation reaction at any time and in any suitablemanner, e.g. to maintain a predetermined level of free ligand in thereaction medium.

As indicated above, the hydroformylation catalyst may be inheterogeneous form during the reaction and/or during the productseparation. Such catalysts are particularly advantageous in thehydroformylation of olefins to produce high boiling or thermallysensitive aldehydes, so that the catalyst may be separated from theproducts by filtration or decantation at low temperatures. For example,the rhodium catalyst may be attached to a support so that the catalystretains its solid form during both the hydroformylation and separationstages, or is soluble in a liquid reaction medium at high temperaturesand then is precipitated on cooling.

As an illustration, the rhodium catalyst may be impregnated onto anysolid support, such as inorganic oxides, (e.g., alumina, silica,titania, or zirconia) carbon, or ion exchange resins. The catalyst maybe supported on, or intercalated inside the pores of, a zeolite orglass; the catalyst may also be dissolved in a liquid film coating thepores of said zeolite or glass. Such zeolite-supported catalysts areparticularly advantageous for producing one or more regioisomericaldehydes in high selectivity, as determined by the pore size of thezeolite. The techniques for supporting catalysts on solids, such asincipient wetness, which will be known to those skilled in the art. Thesolid catalyst thus formed may still be complexed with one or more ofthe ligands defined above. Descriptions of such solid catalysts may befound in for example: J. Mol. Cat. 1991, 70, 363-368; Catal. Lett. 1991,8, 209-214; J. Organomet. Chem, 1991, 403, 221-227; Nature, 1989, 339,454-455; J. Catal. 1985, 96, 563-573; J. Mol. Cat. 1987, 39, 243-259.

The rhodium catalyst may be attached to a thin film or membrane support,such as cellulose acetate or polyphenylenesulfone, as described in forexample J. Mol. Cat. 1990, 63, 213-221.

The rhodium catalyst may be attached to an insoluble polymeric supportthrough an organophosphorus-containing ligand, such as a phosphine orphosphite, incorporated into the polymer. Such polymer-supported ligandsare well known, and include such commercially available species as thedivinylbenzene/polystyrene-supported triphenylphosphine. The supportedligand is not limited by the choice of polymer or phosphorus-containingspecies incorporated into it. Descriptions of polymer-supportedcatalysts may be found in for example: J. Mol. Cat. 1993, 83, 17-35;Chemtech 1983, 46; J. Am. Chem. Soc. 1987, 109, 7122-7127.

In the heterogeneous catalysts described above, the catalyst may remainin its heterogeneous form during the entire hydroformylation andcatalyst separation process. In another embodiment of the invention, thecatalyst may be supported on a polymer which, by the nature of itsmolecular weight, is soluble in the reaction medium at elevatedtemperatures, but precipitates upon cooling, thus facilitating catalystseparation from the reaction mixture. Such "soluble" polymer-supportedcatalysts are described in for example: Polymer, 1992, 33, 161; J. Org.Chem. 1989, 54, 2726-2730.

When the rhodium catalyst is in a heterogeneous or supported form, thereaction is carried out in the slurry phase due to the high boilingpoints of the products, and to avoid decomposition of the productaldehyde acids or salts. The catalyst may then be separated from theproduct mixture by filtration or decantation.

Pentenoic acid salts useful in the hydroformylation processes are knownmaterials and can be prepared by the hydroxycarbonylation andneutralization reactions described above. Reaction mixtures comprisingpentenoic acid salts may be useful herein. The amount of pentenoic acidsalts employed in the hydroformylation reaction is not narrowly criticaland can be any amount sufficient to produce formylvaleric acid salts,preferably in high selectivities.

The hydroformylation reaction conditions may include any suitable typehydroformylation conditions heretofore employed for producing aldehydes.For instance, the total gas pressure of hydrogen, carbon monoxide andother components of the hydroformylation process may range from about 1to about 10,000 psia. In general, the hydroformylation process isoperated at a total gas pressure of hydrogen, carbon monoxide and allother components of less than about 1500 psia and more preferably lessthan about 1000 psia, the minimum total pressure being limitedpredominately by the amount of reactants necessary to obtain a desiredrate of reaction. The total pressure employed in the hydroformylationreaction may range in general from about 20 to about 3000 psia,preferably from about 50 to 2000 psia and more preferably from about 75to about 1000 psia. The total pressure of the hydroformylation processwill be dependent on the particular catalyst system employed.

More specifically, the carbon monoxide partial pressure of thehydroformylation reaction in general may range from about 1 to about3000 psia, and preferably from about 3 to about 1500 psia, while thehydrogen partial pressure in general may range from about 1 to about3000 psia, and preferably from about 3 to about 1500 psia. In general,the molar ratio of carbon monoxide to gaseous hydrogen may range fromabout 100:1 or greater to about 1:100 or less, the preferred carbonmonoxide to gaseous hydrogen molar ratio being from about 1:10 to about10:1. The carbon monoxide and hydrogen partial pressures will bedependent in part on the particular catalyst system employed.

Carbon monoxide partial pressure should be sufficient for thehydroformylation reaction, e.g., of a pentenoic acid salt to aformylvaleric acid salt, to occur at an acceptable rate, but not soextreme that reaction rate and/or normal/branched aldehyde ratio maybecome unacceptably low. Hydrogen partial pressure must be sufficientfor the hydroformylation reaction to occur at an acceptable rate, butnot so high that hydrogenation of starting materials and intermediates,or isomerization of intermediates to undesired isomers, occurs. It isunderstood that carbon monoxide and hydrogen can be employed separately,in mixture with each other, i.e., synthesis gas, or may be produced insitu under reaction conditions.

Further, the hydroformylation process may be conducted at a reactiontemperature from about 20° C. to about 200° C., preferably from about50° C. to about 150° C., and more preferably from about 65° C. to about115° C. The temperature must be sufficient for reaction to occur (whichmay vary with catalyst system employed), but not so high that ligand orcatalyst decomposition occurs. At high temperatures (which may vary withcatalyst system employed), isomerization of intermediates to undesiredisomers may occur.

Of course, it is to be also understood that the hydroformylationreaction conditions employed will be governed by the type of aldehydeacid or salt product desired.

The hydroformylation reactions may also be conducted in the presence ofwater or an organic solvent for the metal-ligand complex catalyst andfree ligand. Depending on the particular catalyst and reactantsemployed, suitable organic solvents include, for example, alcohols,alkanes, alkenes, alkynes, ethers, aldehydes, higher boiling aldehydecondensation byproducts, ketones, esters, amides, tertiary amines,aromatics and the like. Any suitable solvent which does not undulyadversely interfere with the intended hydroformylation reaction can beemployed and such solvents may include those disclosed heretoforecommonly employed in known metal catalyzed hydroformylation reactions.Mixtures of one or more different solvents may be employed if desired.In general, with regard to the production of aldehyde acids or salts,one may employ aldehyde acid or salt compounds corresponding to thealdehyde acid or salt products desired to be produced and/or higherboiling aldehyde liquid condensation byproducts as the main organicsolvents as is common in the art. Such aldehyde condensation byproductscan also be preformed if desired and used accordingly. Illustrativepreferred solvents employable in the production of aldehyde acids orsalts include ketones (e.g. acetone and methylethyl ketone), esters(e.g. ethyl acetate), hydrocarbons (e.g. toluene), nitrohydrocarbons(e.g. nitrobenzene), ethers (e.g. tetrahydrofuran (THF) and glyme),1,4-butanediols and sulfolane. Suitable solvents are disclosed in U.S.Pat. No. 5,312,996. The amount of solvent employed is not critical tothe subject invention and need only be that amount sufficient tosolubilize the catalyst and free ligand of the hydroformylation reactionmixture to be treated. In general, the amount of solvent may range fromabout 5 percent by weight up to about 99 percent by weight or more basedon the total weight of the hydroformylation reaction mixture startingmaterial.

In an embodiment of the invention, the hydroformylation reaction mixturemay consist of one or more liquid phases, e.g. a polar and a nonpolarphase. The reaction can be conducted in a liquid phase from which theproduct and/or catalyst can be separated by extraction into a separateliquid phase. A product-containing phase may also spontaneously separateduring or after the reaction. Such processes are often advantageous in,for example, separating products from catalyst and/or reactants bypartitioning into either phase. In addition, product selectivitiesdependent upon solvent properties may be increased by carrying out thereaction in that solvent. A well-known application of this technology isthe aqueous-phase hydroformylation of olefins employing sulfonatedphosphine ligands for the rhodium catalyst. A process carried out inaqueous solvent is particularly advantageous for the preparation ofaldehyde acids or salts because the products may be separated from thecatalyst by extraction into an organic solvent. Alternatively, aldehydeswhich tend to undergo self-condensation reactions, are expected to bestabilized in aqueous solution as the aldehyde hydrates.

As described herein, the phosphorus-containing ligand for the rhodiumhydroformylation catalyst may contain any of a number of substituents,such as cationic or anionic substituents, which will render the catalystsoluble in a polar phase, e.g. water. Optionally, a phase-transfercatalyst may be added to the reaction mixture to facilitate transport ofthe catalyst, reactants, or products into the desired solvent phase. Thestructure of the ligand or the phase-transfer catalyst is not criticaland will depend on the choice of conditions, reaction solvent, anddesired products.

When the catalyst is present in a multiphasic system, the catalyst maybe separated from the reactants and/or products by conventional methodssuch as extraction or decantation. The reaction mixture itself mayconsist of one or more phases; alternatively, the multiphasic system maybe created at the end of the reaction by for example addition of asecond solvent to separate the products from the catalyst. See, forexample, U.S. Pat. No. 5,180,854, the disclosure of which isincorporated herein by reference.

In an embodiment of the process of this invention, an olefin can behydroformylated along with a pentenoic acid or salt using theabove-described metal-ligand complex catalysts. In such cases, analdehyde derivative of the olefin is also produced along with theformylvaleric acid or salt.

Mixtures of different olefinic starting materials can be employed, ifdesired, in the hydroformylation reactions. More preferably thehydroformylation reactions are especially useful for the production offormylvaleric acid salts, by hydroformylating pentenoic acids or saltsin the presence of alpha olefins containing from 2 to 30, preferably 4to 20, carbon atoms, including isobutylene, and internal olefinscontaining from 4 to 20 carbon atoms as well as starting materialmixtures of such alpha olefins and internal olefins. Commercial alphaolefins containing four or more carbon atoms may contain minor amountsof corresponding internal olefins and/or their corresponding saturatedhydrocarbon and that such commercial olefins need not necessarily bepurified from same prior to being hydroformylated.

Illustrative of other olefinic starting materials include alpha-olefins,internal olefins, 1,3-dienes, alkyl alkenoates, alkenyl alkanoates,alkenyl alkyl ethers, alkenols, alkenals, and the like, e.g., ethylene,propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene,1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene,1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene,2-butene, 2-methyl propene (isobutylene), 2-methylbutene, 2-pentene,2-hexene, 3-hexane, 2-heptene, cyclohexene, propylene dimers, propylenetrimers, propylene tetramers, piperylene, isoprene, 2-ethyl-1-hexene,2-octene, styrene, 3-phenyl-1-propene, 1,4-hexadiene, 1,7-octadiene,3-cyclohexyl-1-butene, allyl alcohol, allyl butyrate, hex-1-en-4-ol,oct-1-en-4-ol, vinyl acetate, allyl acetate, 3-butenyl acetate, vinylpropionate, allyl propionate, methyl methacrylate, vinyl ethyl ether,vinyl methyl ether, vinyl cyclohexene, allyl ethyl ether, methylpentenoate, 3-pentenoic acid, n-propyl-7-octenoate, pentenals, e.g.,2-pentenal, 3-pentenal and 4-pentenal; pentenols, e.g., 2-pentenol,3-pentenol and 4-pentenol; 3-butenenitrile, 3-pentenenitrile,5-hexenamide, 4-methyl styrene, 4-isopropyl styrene, 4-tert-butylstyrene, alpha-methyl styrene, 4-tert-butyl-alpha-methyl styrene,1,3-diisopropenylbenzene, eugenol, iso-eugenol, safrole, iso-safrole,anethol, 4-allylanisole, indene, limonene, beta-pinene,dicyclopentadiene, cyclooctadiene, camphene, linalool, and the like.Other illustrative olefinic compounds may include, for example,p-isobutylstyrene, 2-vinyl-6-methoxynaphthylene, 3-ethenylphenyl phenylketone, 4-ethenylphenyl-2-thienylketone, 4-ethenyl-2-fluorobiphenyl,4-(1,3-dihydro-1-oxo-2H-isoindol-2-yl)styrene,2-ethenyl-5-benzoylthiophene, 3-ethenylphenyl phenyl ether,propenylbenzene, isobutyl-4-propenylbenzene, phenyl vinyl ether and thelike. Other olefinic compounds include substituted aryl ethylenes asdescribed in U.S. Pat. No. 4,329,507, the disclosure of which isincorporated herein by reference.

As indicated above, it is generally preferred to carry out the singlestep process of this invention in a continuous manner. In general, thecontinuous single step process may involve: (a) hydroxycarbonylatingalkadiene starting materials) with carbon monoxide and water in a liquidhomogeneous reaction mixture comprising a solvent, ametal-organophosphorus ligand complex catalyst, free organophosphorusligand and a promoter to produce unsaturated acids; (b) optionallyneutralizing the unsaturated acids with a base to produce unsaturatedacid salts; (c) after a pressure let-down, hydroformylating theunsaturated acid or salt intermediate materials) with carbon monoxideand hydrogen in a liquid homogeneous reaction mixture comprising asolvent, a metal-organophosphorus ligand complex catalyst, and freeorganophosphorus ligand; (d) maintaining reaction temperature andpressure conditions favorable to the hydroxycarbonylation,neutralization and hydroformylation reactions (e) supplying make-upquantities of the starting materials) to the reaction mediums as thosereactants are used up; and (f) recovering the desired aldehyde acid orsalt product(s) in any manner desired. The continuous process can becarried out in a single pass mode, i.e., wherein the aldehyde acid orsalt product is removed from the liquid reaction mixture from whence aproduct is recovered and make-up starting material(s) are supplied tothe liquid reaction medium for the next single pass through withoutrecycling the unreacted starting material(s). However, it is generallydesirable to employ a continuous process that involves either a liquidand/or gas recycle procedure. Such types of recycle procedure are wellknown in the art and may involve the liquid recycling of themetal-ligand complex catalyst solution separated from the desiredaldehyde acid or salt reaction product(s), such as disclosed e.g., inU.S. Pat. No. 4,148,830 or a gas cycle procedure such as disclosed e.g.,in U.S. Pat. No. 4,247,486, as well as a combination of both a liquidand gas recycle procedure if desired. The disclosures of said U.S. Pat.Nos. 4,148,830 and 4,247,486 are incorporated herein by referencethereto. The most preferred hydroformylation process of this inventioncomprises a continuous liquid catalyst recycle process.

Illustrative substituted and unsubstituted aldehyde acids that can beprepared by the processes of this invention include substituted andunsubstituted formylcarboxylic acids such as 5-formylvaleric acids andthe like, e.g., 5-formylvaleric acid. Illustrative of suitablesubstituted and unsubstituted aldehyde acids (including derivatives ofsubstituted and unsubstituted aldehyde acids) include those permissiblesubstituted and unsubstituted aldehyde acids which may be described inKirk-Othmer, Encyclopedia of Chemical Technology, Fourth Edition, 1996,the pertinent portions of which are incorporated herein by reference.

Illustrative substituted and unsubstituted aldehyde acid salts that canbe prepared by the processes of this invention include substituted andunsubstituted formylcarboxylic acid salts such as 5-formylvaleric acidsalts and the like, e.g., triethylammonium 5- formylvalerate, ammonium5-formylvalerate and octyltriethylammonium 5-formylvalerate.Illustrative of suitable substituted and unsubstituted aldehyde acidsalts (including derivatives of substituted and unsubstituted aldehydeacid salts) include those permissible substituted and unsubstitutedaldehyde acid salts which are described in Kirk-Othmer, Encyclopedia ofChemical Technology, Fourth Edition, 1996, the pertinent portions ofwhich may be incorporated herein by reference.

Illustrative substituted and unsubstituted epsilon caprolactamprecursors that can be prepared by the processes of this inventioninclude one or more substituted and unsubstituted 5-formylvaleric acidand/or salts thereof, iminocaproic acid and/or salts thereof,aminocaproic acid and/or salts thereof, caprolactam, caprolactone,imines, hemiaminals, imides, amides or amines derived from formylvalericacid and its salts, and the corresponding dimers, trimers and oligomers.Illustrative of suitable substituted and unsubstituted epsiloncaprolactam precursors (including derivatives of substituted andunsubstituted epsilon caprolactam precursors) include those permissiblesubstituted and unsubstituted epsilon caprolactam precursors which maybe described in Kirk-Othmer, Encyclopedia of Chemical Technology, FourthEdition, 1996, the pertinent portions of which are incorporated hereinby reference.

In an embodiment of this invention, the aldehyde acid or salt mixturesmay be separated from the other components of the crude reactionmixtures in which the aldehyde acid or salt mixtures are produced by anysuitable method. Suitable separation methods include, for example,solvent extraction, crystallization, distillation, vaporization, phaseseparation, sublimation, wiped film evaporation, falling filmevaporation and the like. It may be desired to remove the aldehyde acidor salt products from the crude reaction mixture as they are formedthrough the use of trapping agents as described in published PatentCooperation Treaty Patent Application WO 88/08835. A method forseparating the aldehyde acid or salt mixtures from the other componentsof the crude reaction mixtures is by membrane separation. Such membraneseparation can be achieved as set out in U.S. Pat. No. 5,430,194 andcopending U.S. patent application Ser. No. 08/430,790, filed May 5,1995, both incorporated herein by reference.

Particularly when conducting the process of this invention in acontinuous liquid recycle mode employing an organophosphite ligand,undesirable acidic byproducts (e.g., a hydroxy alkyl phosphonic acid)may result due to reaction of the organophosphite ligand and thealdehyde over the course of the process. The formation of suchbyproducts undesirably lowers the concentration of the ligand. Suchacids are often insoluble in the reaction mixture and such insolubilitycan lead to precipitation of an undesirable gelatinous byproduct and mayalso promote the autocatalytic formation of further acidic byproducts.The organopolyphosphite ligands used in the process of this inventionhave good stability against the formation of such acids. However, ifthis problem does occur, the liquid reaction effluent stream of acontinuous liquid recycle process may be passed, prior to (or morepreferably after) separation of the desired 5-formylvaleric acid or saltproduct therefrom, through any suitable weakly basic anion exchangeresin, such as a bed of amine Amberlyst® resin, e.g., Amberlyst® A-21,and the like, to remove some or all of the undesirable acidic byproductsprior to its reincorporation into the hydroformylation reactor. Ifdesired, more than one such basic anion exchange resin bed, e.g. aseries of such beds, may be employed and any such bed may be easilyremoved and/or replaced as required or desired. Alternatively ifdesired, any part or all of the acid-contaminated catalyst recyclestream may be periodically removed from the continuous recycle operationand the contaminated liquid so removed treated in the same fashion asoutlined above, to eliminate or reduce the amount of acidic by-productprior to reusing the catalyst containing liquid in the hydroformylationprocess. Likewise, any other suitable method for removing such acidicbyproducts from the hydroformylation process of this invention may beemployed herein if desired such as by extraction of the acid with a weakbase (e.g., sodium bicarbonate).

The processes useful in this invention may involve improving thecatalyst stability of any organic solubilizedrhodium-organopolyphosphite complex catalyzed, liquid recyclehydroformylation process directed to producing aldehydes from olefinicunsaturated compounds which may experience deactivation of the catalystdue to recovery of the aldehyde product by vaporization separation froma reaction product solution containing the organic solubilizedrhodium-organopolyphosphite complex catalyst and aldehyde product, theimprovement comprising carrying out said vaporization separation in thepresence of a heterocyclic nitrogen compound. See, for example,copending U.S. patent application Ser. No. 08/756,789, filed Nov. 26,1996, the disclosure of which is incorporated herein by reference.

The processes useful in this invention may involve improving thehydrolytic stability of the organophosphite ligand and thus catalyststability of any organic solubilized rhodium-organophosphite ligandcomplex catalyzed hydroformylation process directed to producingaldehydes from olefinic unsaturated compounds, the improvementcomprising treating at least a portion of an organic solubilizedrhodium-organophosphite ligand complex catalyst solution derived fromsaid process and which also contains phosphorus acidic compounds formedduring the hydroformylation process, prior to (or more preferably after)separation of the desired aldehyde acid or salt product therefrom, withan aqueous buffer solution in order to neutralize and remove at leastsome amount of said phosphorus acidic compounds from said catalystsolution, and then returning the treated catalyst solution to thehydroformylation reactor. See, for example, copending U.S. patentapplication Ser. Nos. 08/756,501 and 08/753,505, both filed Nov. 26,1996, the disclosures of which are incorporated herein by reference.

In an embodiment of this invention, deactivation ofmetal-organopolyphosphorus ligand complex catalysts caused by aninhibiting or poisoning organomonophosphorus compound can be reversed orat least minimized by carrying out hydroformylation processes in areaction region where the hydroformylation reaction rate is of anegative or inverse order in carbon monoxide and optionally at one ormore of the following conditions: at a temperature such that thetemperature difference between reaction product fluid temperature andinlet coolant temperature is sufficient to prevent and/or lessen cyclingof carbon monoxide partial pressure, hydrogen partial pressure, totalreaction pressure, hydroformylation reaction rate and/or temperatureduring said hydroformylation process; at a carbon monoxide conversionsufficient to prevent and/or lessen cycling of carbon monoxide partialpressure, hydrogen partial pressure, total reaction pressure,hydroformylation reaction rate and/or temperature during saidhydroformylation process; at a hydrogen conversion sufficient to preventand/or lessen cycling of carbon monoxide partial pressure, hydrogenpartial pressure, total reaction pressure, hydroformylation reactionrate and/or temperature during said hydroformylation process; and at anolefinic unsaturated compound conversion sufficient to prevent and/orlessen cycling of carbon monoxide partial pressure, hydrogen partialpressure, total reaction pressure, hydroformylation reaction rate and/ortemperature during said hydroformylation process. See, for example,copending U.S. patent application Ser. No. 08/756,499, filed Nov. 26,1996, the disclosure of which is incorporated herein by reference.

The aldehyde acid or salt products described herein are useful in avariety of applications, such as chemical intermediates for producingepsilon caprolactam.

The processes of this invention can be operated over a wide range ofreaction rates (m/L/h=moles of product/liter of reaction solution/hour).Typically, the reaction rates are at least 0.01 m/L/h or higher,preferably at least 0.1 m/L/h or higher, and more preferably at least0.5 m/L/h or higher. Higher reaction rates are generally preferred froman economic standpoint, e.g., smaller reactor size, etc.

A process for producing one or more substituted or unsubstitutedaldehyde acid salts from one or more substituted or unsubstitutedunsaturated acid salts is disclosed in copending U.S. patent applicationSer. No. (08/834,248), filed on an even date herewith, the disclosure ofwhich is incorporated herein by reference.

The processes of this invention may be carried out using, for example, afixed bed reactor, a fluid bed reactor, or a slurry reactor. The optimumsize and shape of the catalysts will depend on the type of reactor used.In general, for fluid bed reactors, a small, spherical catalyst particleis preferred for easy fluidization. With fixed bed reactors, largercatalyst particles are preferred so the back pressure within the reactoris kept reasonably low.

The processes of this invention can be conducted in a batch orcontinuous fashion, with recycle of unconsumed starting materials ifrequired. The reaction can be conducted in a single reaction zone or ina plurality of reaction zones, in series or in parallel or it may beconducted batchwise or continuously in an elongated tubular zone orseries of such zones. The materials of construction employed should beinert to the starting materials during the reaction and the fabricationof the equipment should be able to withstand the reaction temperaturesand pressures. Means to introduce and/or adjust the quantity of startingmaterials or ingredients introduced batchwise or continuously into thereaction zone during the course of the reaction can be convenientlyutilized in the processes especially to maintain the desired molar ratioof the starting materials. The reaction stages may be effected by theincremental addition of one of the starting materials to the other.Also, the reaction stages can be combined by the joint addition of thestarting materials. When complete conversion is not desired or notobtainable, the starting materials can be separated from the product,for example by distillation, and the starting materials then recycledback into the reaction zone.

The processes may be conducted in either glass lined, stainless steel orsimilar type reaction equipment. The reaction zone may be fitted withone or more internal and/or external heat exchanger(s) in order tocontrol undue temperature fluctuations, or to prevent any possible"runaway" reaction temperatures.

In an embodiment, the processes useful in this invention may be carriedout in a multistaged reactor such as described, for example, incopending U.S. patent application Ser. No.08/757,743, filed on Nov. 26,1996, the disclosure of which is incorporated herein by reference. Suchmultistaged reactors can be designed with internal, physical barriersthat create more than one theoretical reactive stage per vessel. Ineffect, it is like having a number of reactors inside a singlecontinuous stirred tank reactor vessel. Multiple reactive stages withina single vessel is a cost effective way of using the reactor vesselvolume. It significantly reduces the number of vessels that otherwisewould be required to achieve the same results. Fewer vessels reduces theoverall capital required and maintenance concerns with separate vesselsand agitators.

The substituted and unsubstituted aldehyde acids or salts produced bythe processes of this invention can undergo further reaction(s) toafford desired derivatives thereof. Such permissible derivatizationreactions can be carried out in accordance with conventional proceduresknown in the art. Illustrative derivatization reactions include, forexample, hydrogenation, esterification, reductive amination,cyclization, reductive cyclization, polymerization, copolymerization,amination, alkylation, dehydrogenation, reduction, acylation,condensation, oxidation, silylation and the like, including permissiblecombinations thereof. This invention is not intended to be limited inany manner by the permissible derivatization reactions or permissiblederivatives of substituted and unsubstituted aldehyde acids or salts.

For purposes of this invention, the term "hydrocarbon" is contemplatedto include all permissible compounds having at least one hydrogen andone carbon atom. Such permissible compounds may also have one or moreheteroatoms. In a broad aspect, the permissible hydrocarbons includeacyclic (with or without heteroatoms) and cyclic, branched andunbranched, carbocyclic and heterocyclic, aromatic and nonaromaticorganic compounds which can be substituted or unsubstituted.

As used herein, the term "substituted" is contemplated to include allpermissible substituents of organic compounds unless otherwiseindicated. In a broad aspect, the permissible substituents includeacyclic and cyclic, branched and unbranched, carbocyclic andheterocyclic, aromatic and nonaromatic substituents of organiccompounds. Illustrative substituents include, for example, alkyl,alkyloxy, aryl, aryloxy, hydroxy, hydroxyalkyl, amino, aminoalkyl,halogen and the like in which the number of carbons can range from 1 toabout 20 or more, preferably from 1 to about 12. The permissiblesubstituents can be one or more and the same or different forappropriate organic compounds. This invention is not intended to belimited in any manner by the permissible substituents of organiccompounds.

For purposes of this invention, the chemical elements are identified inaccordance with the Periodic Table of the Elements reproduced in "BasicInorganic Chemistry" by F. Albert Cotton, Geoffrey Wilkinson and Paul L.Gaus, published by John Wiley and Sons, Inc., 3rd Edition, 1995.

Certain of the following examples are provided to further illustratethis invention.

EXAMPLE 1

A 100 milliliter Parr autoclave was charged with 0.05 grams of PdCl₂(1000 ppm Pd), 0.02 grams of dicarbonylacetylacetonato rhodium (I) (300ppm rhodium), and 1.01 grams of Ligand F identified above (5 mol ligandper mole palladium). The reactor was sealed and purged with nitrogen,then 25 milliliters of dry 1,4-dioxane, 1 milliliter of butadiene, 0.4milliliters of water (2 moles per mole butadiene) and 1.09 grams ofN-methylpyrrolidinone (as an internal standard) were added via syringe.The reaction mixture was pressurized with 1400 psi carbon monoxide, andheated to 110° C. After 3 hours reaction time, the mixture was analyzedby gas chromatography. Butadiene was 55% converted to 3-pentenoic acid.The reactor was cooled to 40° C., and the headspace gases were vented toapproximately 40 psi. The reactor was then pressurized with 1000 psi 1:1carbon monoxide:hydrogen and heated to 110° C. After 2 hours analysis bygas chromatography showed the 3-pentenoic acid 60% converted. Thehydroformylation products contained 40.2% of 5-formylvaleric acid, 27%of branched aldehyde acids, and 15% of valeric acid.

EXAMPLE 2

A 100 milliliter Parr autoclave was charged with 0.15 grams of palladiumbis(dibenzylideneacetone) (1000 ppm Pd), and 0.44 grams of Ligand Fidentified above (2 mol ligand per mole palladium). The reactor wassealed and purged with nitrogen, then 25 milliliters of dry 1,4-dioxane,34 microliters of 57% aqueous HI (1 mole iodide per mole palladium), 3milliliters of butadiene, 1.2 milliliters of water (2 moles per molebutadiene) and 1.09 grams of N-methylpyrrolidinone (as an internalstandard) were added via syringe. The reaction mixture was pressurizedwith 1300 psi carbon monoxide, and heated to 110° C. After 3.5 hoursreaction time, the mixture was analyzed by gas chromatography. Butadienewas 73% converted. The product mixture contained 97.6% of 3-pentenoicacid, 1.4% of 4-pentenoic acid, 1.0% of valeric acid. The reactor wascooled, and the headspace gases were vented off. A solution consistingof 0.02 grams of dicarbonylacetylacetonato rhodium (I) and 0.22 grams ofLigand F identified above (3 moles ligand per mole rhodium) in 5milliliters of 1,4-dioxane was then added to the reaction mixture viasyringe. The reactor was pressurized with 1000 psi 1:1 carbonmonoxide:hydrogen and heated to 110° C. After 1 hour analysis by gaschromatography showed the 3-pentenoic acid 15% converted to5-formylvaleric acid.

EXAMPLE 3

A 100 milliliter Parr autoclave was charged with 0.15 grams of palladiumbis(dibenzylideneacetone) (1000 ppm Pd), and 0.45 grams of Ligand Fidentified above (2 mol ligand per mole palladium). The reactor wassealed and purged with nitrogen, then 25 milliliters of dry 1,4-dioxane,34 microliters of 57% aqueous HI (1 mole iodide per mole palladium), 1milliliter of butadiene, 0.4 milliliters of water (2 moles per molebutadiene) and 1.07 grams of N-methylpyrrolidinone (as an internalstandard) were added via syringe. The reaction mixture was pressurizedwith 1300 psi carbon monoxide, and heated to 110° C. After 2 hoursreaction time, the mixture was analyzed by gas chromatography. Butadienewas 98% converted to 3-pentenoic acid. The reactor was cooled, and theheadspace gases were vented to approximately 10 psi. A solutionconsisting of 0.017 grams of dicarbonylacetylacetonato rhodium (I) and0.28 grams of Ligand F identified above (5 moles ligand per molerhodium) in 5 milliliters of 1,4-dioxane was then added to the reactionmixture via syringe. The reactor was pressurized with 500 psi 1:1 carbonmonoxide:hydrogen and heated to 110° C. After 1 hour the syngas pressurewas raised to 1000 psi. After 3 hours analysis by gas chromatographyshowed the 3-pentenoic acid was 51% converted. The hydroformylationproducts consisted of 60.4% of 5-formylvaleric acid, 26.9% of branchedacids and 12.7% of valeric acid.

EXAMPLE 4

A 100 milliliter Parr autoclave was charged with 0.15 grams of palladiumbis(dibenzylideneacetone) (1000 ppm Pd), 0.024 grams ofdicarbonylacetylacetonato rhodium (I) (300 ppm Rh), and 0.73 grams ofLigand F identified above (2 mol ligand per mole palladium plus 3 molesligand per mole rhodium). The reactor was sealed and purged withnitrogen, then 25 milliliters of dry 1,4-dioxane, 34 microliters of 57%aqueous HI (1 mole iodide per mole palladium), 1 milliliter ofbutadiene, 0.4 milliliters of water (2 moles per mole butadiene) and1.09 grams of N-methylpyrrolidone (as an internal standard) were addedvia syringe. The reaction mixture was pressurized with 1300 psi carbonmonoxide, and heated to 110° C. After 2 hours reaction time, the mixturewas analyzed by gas chromatography. Butadiene was 33% converted to3-pentenoic acid. The reactor was cooled to 36° C., and the headspacegases were vented to approximately 20 psi. The reactor was thenpressurized with 1200 psi 1:1 carbon monoxide:hydrogen and heated to110° C. After 3 hours analysis by gas chromatography showed the3-pentenoic acid was 17% converted. The hydroformylation productsconsisted of 72.1% of 5-formylvaleric acid and 28% of branched aldehydeacids.

EXAMPLE 5

A 100 milliliter Parr autoclave was charged with 0.11 grams of palladiumbis(dibenzylideneacetone) (750 ppm Pd), and 0.33 grams of Ligand Fidentified above (2 mol ligand per mole palladium). The reactor wassealed and purged with nitrogen, then 25 milliliters of dry 1,4-dioxane,26 microliters of 57% aqueous HI (1 mole iodide per mole palladium), 1milliliter of butadiene, 0.4 milliliters of water (2 moles per molebutadiene) and 1.08 grams of N-methylpyrrolidinone (as an internalstandard) were added via syringe. The reaction mixture was pressurizedwith 1250 psi carbon monoxide, and heated to 110° C. After 3.5 hoursreaction time, the mixture was analyzed by gas chromatography. Butadienewas 92% converted to 3-pentenoic acid. The reactor was cooled, and theheadspace gases were vented to approximately 20 psi. A solutionconsisting of 0.084 grams of dicarbonylacetylacetonato rhodium (I) (1250ppm rhodium) and 0.82 grams of Ligand F identified above (3 moles ligandper mole rhodium) in 5 milliliters of 1,4-dioxane was then added to thereaction mixture via syringe. The reactor was pressurized with 300 psi1:1 carbon monoxide:hydrogen and heated to 85° C. After 2.5 hoursanalysis by gas chromatography showed complete conversion of 3-pentenoicacid. The hydroformylation products contained 64.2% of 5-formylvalericacid, 21.7% of branched aldehyde acids and 9.3% of valeric acid.

Although the invention has been illustrated by certain of the precedingexamples, it is not to be construed as being limited thereby; butrather, the invention encompasses the generic area as hereinbeforedisclosed. Various modifications and embodiments can be made withoutdeparting from the spirit and scope thereof.

We claim:
 1. A process for producing one or more substituted orunsubstituted aldehyde acids which comprises subjecting one or moresubstituted or unsubstituted alkadienes to hydroxycarbonylation in thepresence of a hydroxycarbonylation catalyst to produce one or moresubstituted or unsubstituted unsaturated acids and subjecting said oneor more substituted or unsubstituted unsaturated acids tohydroformylation in the presence of a hydroformylation catalyst toproduce said one or more substituted or unsubstituted aldehyde acidsand/or one or more substituted or unsubstituted epsilon caprolactamprecursors, wherein the hydroxycarbonylation and hydroformylationcatalysts may be the same or different and comprise a metal-ligandcomplex catalyst which comprises a metal selected from a Group 8, 9 and10 metal complexed with an organophosphorus ligand selected from amono-, di-, tri- and poly-(organophosphine) ligand or a mono-, di-, tri-and poly-(organophosphite) ligand.
 2. A process for producing one ormore substituted or unsubstituted aldehyde acid salts which comprisessubjecting one or more substituted or unsubstituted alkadienes tohydroxycarbonylation in the presence of a hydroxycarbonylation catalystand neutralization with a base to produce one or more substituted orunsubstituted unsaturated acid salts and subjecting said one or moresubstituted or unsubstituted unsaturated acid salts to hydroformylationin the presence of a hydroformylation catalyst to produce said one ormore substituted or unsubstituted aldehyde acid salts and/or one or moresubstituted or unsubstituted epsilon caprolactam precursors, wherein thehydroxycarbonylation and hydroformylation catalysts may be the same ordifferent and comprise a metal-ligand complex catalyst which comprises ametal selected from a Group 8, 9 and 10 metal complexed with anorganophosphorus ligand selected from a mono-, di-, tri- andpoly-(organophosphine) ligand or a mono-, di-, tri- andpoly-(organophosphite) ligand.
 3. A process for producing one or moresubstituted or unsubstituted aldehyde acids which comprises reacting oneor more substituted or unsubstituted alkadienes with carbon monoxide andwater in the presence of a metal-ligand complex catalyst and a promoterto produce one or more substituted or unsubstituted unsaturated acids,and reacting said one or more substituted or unsubstituted unsaturatedacids with carbon monoxide and hydrogen in the presence of ametal-ligand complex catalyst and optionally free ligand to produce saidone or more substituted or unsubstituted aldehyde acids and/or one ormore substituted or unsubstituted epsilon caprolactam precursors,wherein the metal-ligand complex catalysts may be the same or differentand comprise a metal selected from a Group 8, 9 and 10 metal complexedwith an organophosphorus ligand selected from a mono-, di-, tri- andpoly-(organophosphine) ligand or a mono-, di-, tri- andpoly-(organophosphite) ligand.
 4. A process for producing one or moresubstituted or unsubstituted aldehyde acid salts which comprisesreacting one or more substituted or unsubstituted alkadienes with carbonmonoxide and water in the presence of a metal-ligand complex catalystand a promoter and a base to produce one or more substituted orunsubstituted unsaturated acid salts, and reacting said one or moresubstituted or unsubstituted unsaturated acid salts with carbon monoxideand hydrogen in the presence of a metal-ligand complex catalyst andoptionally free ligand to produce said one or more substituted orunsubstituted aldehyde acid salts and/or one or more substituted orunsubstituted epsilon caprolactam precursors, wherein the metal-ligandcomplex catalysts may be the same or different and comprise a metalselected from a Group 8, 9 and 10 metal complexed with anorganophosphorus ligand selected from a mono-, di-, tri- andpoly-(organophosphine) ligand or a mono-, di-, tri- andpoly-(organophosphite) ligand.
 5. The process of claim 1 wherein thesubstituted or unsubstituted alkadiene comprises butadiene, thesubstituted or unsubstituted unsaturated acid comprises 3-pentenoicacid, 4-pentenoic acid and/or 2-pentenoic acid, and the substituted orunsubstituted aldehyde acid comprises 5-formylvaleric acid.
 6. Theprocess of claim 2 wherein the substituted or unsubstituted alkadienecomprises butadiene, the substituted or unsubstituted unsaturated acidsalt comprises 3-pentenoic acid salt, 4-pentenoic acid salt and/or2-pentenoic acid salt, and the substituted or unsubstituted aldehydeacid salt comprises 5-formylvaleric acid salt.
 7. The process of claim 1wherein the hydroxycarbonylation reaction is conducted in the presenceof promoter comprising an organic acid or salt, an inorganic acid orsalt, a Lewis acid or an acyl halide.
 8. The process of claim 1 whereinthe hydroxycarbonylation and hydroformylation reaction conditions may bethe same or different.
 9. The process of claim 1 wherein saidmetal-ligand complex catalyst comprises a metal selected from a Group 8,9 and 10 metal complexed with an organophosphorus ligand selectedfrom:(i) a triorganophosphine ligand represented by the formula:##STR11## wherein each R¹ is the same or different and is a substitutedor unsubstituted monovalent hydrocarbon radical; (ii) amonoorganophosphite represented by the formula: ##STR12## wherein R³represents a substituted or unsubstituted trivalent hydrocarbon radicalcontaining from 4 to 40 carbon atoms or greater; (iii) adiorganophosphite represented by the formula: ##STR13## wherein R⁴represents a substituted or unsubstituted divalent hydrocarbon radicalcontaining from 4 to 40 carbon atoms or greater and W represents asubstituted or unsubstituted monovalent hydrocarbon radical containingfrom 1 to 18 carbon atoms or greater; (iv) a triorganophosphiterepresented by the formula: ##STR14## wherein each R⁸ is the same ordifferent and is a substituted or unsubstituted monovalent hydrocarbonradical; and (v) an organopolyphosphite containing two or more tertiary(trivalent) phosphorus atoms represented by the formula: ##STR15##wherein X¹ represents a substituted or unsubstituted n-valenthydrocarbon bridging radical containing from 2 to 40 carbon atoms, eachR⁹ is the same or different and is a divalent hydrocarbon radicalcontaining from 4 to 40 carbon atoms, each R¹⁰ is the same or differentand is a substituted or unsubstituted monovalent hydrocarbon radicalcontaining from 1 to 24 carbon atoms, a and b can be the same ordifferent and each have a value of 0 to 6, with the proviso that the sumof a+b is 2 to 6 and n equals a+b.
 10. The process of claim 1 whereinsaid metal-ligand complex catalyst comprises a metal selected from aGroup 8, 9 and 10 metal complexed with an organophosphorus ligand havingthe formula: ##STR16## wherein W represents a substituted orunsubstituted monovalent hydrocarbon radical containing from 1 to 18carbon atoms or greater, each Ar is the same or different and representsa substituted or unsubstituted aryl radical, each y is the same ordifferent and is a value of 0 or 1, Q represents a divalent bridginggroup selected from --C(R⁵)₂ --, --O--, --S--, --NR⁶ --, Si(R⁷)₂ -- and--CO--, wherein each R⁵ is the same or different and representshydrogen, alkyl radicals having from 1 to 12 carbon atoms, phenyl,tolyl, and anisyl, R⁶ represents hydrogen or a methyl radical, each R⁷is the same or different and represents hydrogen or a methyl radical,and m is a value of 0 or
 1. 11. The process of claim 1 wherein saidmetal-ligand complex catalyst comprises a metal selected from a Group 8,9 and 10 metal complexed with an organophosphorus ligand having theformula selected from: ##STR17## wherein X¹ represents a substituted orunsubstituted n-valent hydrocarbon bridging radical containing from 2 to40 carbon atoms, each R⁹ is the same or different and is a divalenthydrocarbon radical containing from 4 to 40 carbon atoms, and each R¹⁰is the same or different and is a substituted or unsubstitutedmonovalent hydrocarbon radical containing from 1 to 24 carbon atoms. 12.The process of claim 1 wherein said metal-ligand complex catalystcomprises a metal selected from a Group 8, 9 and 10 metal complexed withan organophosphorus ligand having the formula selected from: ##STR18##wherein X¹ represents a substituted or unsubstituted n-valenthydrocarbon bridging radical containing from 2 to 40 carbon atoms, eachR⁹ is the same or different and is a divalent hydrocarbon radicalcontaining from 4 to 40 carbon atoms, each R¹⁰ is the same or differentand is a substituted or unsubstituted monovalent hydrocarbon radicalcontaining from 1 to 24 carbon atoms, each Ar is the same or differentand represents a substituted or unsubstituted aryl radical, each y isthe same or different and is a value of 0 or 1, Q represents a divalentbridging group selected from --C(R⁵)₂ --, --O--, --S--, --NR⁶⁻, Si(R⁷)₂-- and --CO--, wherein each R⁵ is the same or different and representshydrogen, alkyl radicals having from 1 to 12 carbon atoms, phenyl,tolyl, and anisyl, R⁶ represents hydrogen or a methyl radical, each R⁷is the same or different and represents hydrogen or a methyl radical,and m is a value of 0 or
 1. 13. The process of claim 1 which isconducted at a temperature from about 50° C. to 150° C. and at a totalpressure from about 200 psig to about 1000 psig.
 14. A process forproducing a batchwise or continuously generated reaction mixturecomprising:(1) one or more substituted or unsubstituted aldehyde acidsand/or one or more substituted or unsubstituted epsilon caprolactamprecursors; (2) optionally one or more substituted or unsubstitutedaldehyde acid salts; (3) optionally one or more substituted orunsubstituted unsaturated acids; (4) optionally one or more substitutedor unsubstituted unsaturated acid salts; (5) optionally one or moresubstituted or unsubstituted saturated acids; (6) optionally one or moresubstituted or unsubstituted saturated acid salts; and (7) one or moresubstituted or unsubstituted alkadienes;wherein the weight ratio ofcomponent (1) to the sum of components (2), (3), (4), (5) and (6) isgreater than about 0.1; and the weight ratio of component (7) to the sumof components (1), (2), (3), (4), (5) and (6) is about 0 to about 100;which process comprises subjecting one or more substituted orunsubstituted alkadienes to hydroxycarbonylation in the presence of ahydroxycarbonylation catalyst to produce one or more substituted orunsubstituted unsaturated acids and subjecting said one or moresubstituted or unsubstituted unsaturated acids to hydroformylation inthe presence of a hydroformylation catalyst to produce said batchwise orcontinuously generated reaction mixture, wherein thehydroxycarbonylation and hydroformylation catalysts may be the same ordifferent and comprise a metal-ligand complex catalyst which comprises ametal selected from a Group 8, 9 and 10 metal complexed with anorganophosphorus ligand selected from a mono-, di-, tri- andpoly-(organophosphine) ligand or a mono-, di-, tri- andpoly-(organophosphite) ligand.
 15. A process for producing a batchwiseor continuously generated reaction mixture comprising:(1) one or moresubstituted or unsubstituted aldehyde acid salts and/or one or moresubstituted or unsubstituted epsilon caprolactam precursors; (2)optionally one or more substituted or unsubstituted aldehyde acids; (3)optionally one or more substituted or unsubstituted unsaturated acidsalts; (4) optionally one or more substituted or unsubstitutedunsaturated acids; (5) optionally one or more substituted orunsubstituted saturated acid salts; (6) optionally one or moresubstituted or unsubstituted saturated acids; and (7) one or moresubstituted or unsubstituted alkadienes;wherein the weight ratio ofcomponent (1) to the sum of components (2), (3), (4), (5) and (6) isgreater than about 0.1; and the weight ratio of component (7) to the sumof components (1), (2), (3), (4), (5) and (6) is about 0 to about 100;which process comprises subjecting one or more substituted orunsubstituted alkadienes to hydroxycarbonylation in the presence of ahydroxycarbonylation catalyst and neutralization with a base to produceone or more substituted or unsubstituted unsaturated acid salts andsubjecting said one or more substituted or unsubstituted unsaturatedacid salts to hydroformylation in the presence of a hydroformylationcatalyst to produce said batchwise or continuously generated reactionmixture, wherein the hydroxycarbonylation and hydroformylation catalystsmay be the same or different and comprise a metal-ligand complexcatalyst which comprises a metal selected from a Group 8, 9 and 10 metalcomplexed with an organophosphorus ligand selected from a mono-, di-,tri- and poly-(organophosphine) ligand or a mono-, di-, tri- and-poly-(organophosphite) ligand.
 16. A process for producing a reactionmixture comprising one or more substituted or unsubstituted aldehydeacids which process comprises subjecting one or more substituted orunsubstituted alkadienes to hydroxycarbonylation in the presence of ahydroxycarbonylation catalyst to produce one or more substituted orunsubstituted unsaturated acids and subjecting said one or moresubstituted or unsubstituted unsaturated acids to hydroformylation inthe presence of a hydroformylation catalyst to produce said reactionmixture comprising one or more substituted or unsubstituted aldehydeacids, wherein the hydroxycarbonylation and hydroformylation catalystsmay be the same or different and comprise a metal-ligand complexcatalyst which comprises a metal selected from a Group 8, 9 and 10 metalcomplexed with an organophosphorus ligand selected from a mono-, di-,tri- and poly-(organophosphine) ligand or a mono-, di-, tri- andpoly-(organophosphite) ligand.
 17. A process for producing a reactionmixture comprising one or more substituted or unsubstituted aldehydeacid salts which process comprises subjecting one or more substituted orunsubstituted alkadienes to hydroxycarbonylation in the presence of ahydroxycarbonylation catalyst and neutralization with a base to produceone or more substituted or unsubstituted unsaturated acid salts andsubjecting said one or more substituted or unsubstituted unsaturatedacid salts to hydroformylation in the presence of a hydroformylationcatalyst to produce said one reaction mixture comprising one or moresubstituted or unsubstituted aldehyde acid salts, wherein thehydroxycarbonylation and hydroformylation catalysts may be the same ordifferent and comprise a metal-ligand complex catalyst which comprises ametal selected from a Group 8, 9 and 10 metal complexed with anorganophosphorus ligand selected from a mono-, di-, tri- andpoly-(organophosphine) ligand or a mono-, di-, tri- andpoly-(organophosphite) ligand.